Estudo do Comportamento de Concretos em Ambiente com a Presença de Ácido Sulfúrico e Cloretos

IX \ue003 Congreso \ue003 Internaci onal \ue003 sobre \ue003 Patología \ue003 y \ue003 Recuperación \ue003 de \ue003 Estructuras \ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 IX \ue003 Internationa l \ue003 Congress \ue003 on \ue003 Pathology \ue003 and \ue003 Repair \ue003 of \ue003 Structures \ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 João \ue003 Pesso a \u2010 PB \ue003 (Brasil ), \ue003 2 \ue003 a \ue003 5 \ue003 de \ue003 junho \ue003 de \ue003 2013 \ue003 \ue003 Anais \ue003 do \ue003 IX \ue003 Congresso \ue003 Internacional \ue003 sobre \ue003 Patolog ia \ue003 e \ue003 Recup eraç ão \ue003 de \ue003 Estruturas \ue003 \u2013 \ue003 CINPAR \ue003 2013 \ue003 \ue003 \ue003 Manifestações \ue003 patológicas \ue003 na \ue003 construç ão \ue003 Estudo \ue003 do \ue003 comporta ment o \ue003 de \ue003 concretos \ue003 em \ue003 ambientes \ue003 com \ue003 a \ue003 pres ença \ue003 de \ue003 ácido \ue003 sulfúrico \ue003 e \ue003 cloretos \ue003 Concrete \ue003 behavi our \ue003 study \ue003 in \ue003 environments \ue003 with \ue003 sulphuric \ue003 acid \ue003 and \ue003 chlorides \ue003 \ue003 Pablo \ue003 Ramon \ue003 Rodrigues \ue003 Ferreira \ue003 (1); \ue003 M unique \ue003 Silva \ue003 de \ue003 Lima \ue003 (2); \ue003 Gibson \ue003 Rocha \ue003 Meira \ue003 (3) \ue003 \ue003 (1) Mestrando em Engenharia Civil pela UFPE, e-mail: pablo.r0 6@hotmail.com (2)Mestre em Engenharia de Materiais, Bolsista de Apoio Técnico a Persquisa CNPq, IFPB, e-mail: munique10@gmail.co m (3) Professor Doutor, Departamento de Construção Civil do IFPB, e-mail: gibsonmeira@yahoo.com \ue003 Resumo \ue003 \ue003 As \ue003 estruturas \ue003 de \ue003 concre t o \ue003 ar mado \ue003 submet idas \ue003 à \ue003 influê ncia \ue003 de \ue003 ambientes \ue003 industriais \ue003 podem \ue003 sofrer \ue003 a \ue003 ação \ue003 simultânea \ue003\ue003\ue003 dos \ue003 íons \ue003 cloretos \ue003 e \ue003 substâncias \ue003 ácidas, \ue003 que \ue003 provocam \ue003 a \ue003 redução \ue003 do \ue003 pH \ue003 entorno \ue003 da \ue003 armad ura \ue003 e dissolução \ue003 da \ue003 matriz \ue003 cimentícia. \ue003 O \ue003 presente \ue003 trabalho \ue003 avalia \ue003 o \ue003 comportamento \ue003 da \ue003 mat riz \ue003 de \ue003 concreto \ue003 qua ndo \ue003 submetida \ue003 a \ue003 esse \ue003 tipo \ue003 de \ue003 ambiente. \ue003 Para \ue003 isto, \ue003 foram \ue003 moldados \ue003 corpos \ue003 de \ue003 provas \ue003 co m \ue003 dimensões \ue003 cilíndricas \ue003 de \ue003 10 \ue003 x \ue003 20 \ue003 cm, \ue003 7,5 \ue003 x \ue003 15 \ue003 cm \ue003 nas \ue003 relações \ue003 a/c \ue003 0,3, \ue003 0,4 \ue003 e \ue003 0,5. \ue003 Os \ue003 mesmos \ue003 foram \ue003 submetidos \ue003 a \ue003 ciclos \ue003 de \ue003 imersão \ue003 e \ue003 se cagem \ue003 em \ue003\ue003 soluções \ue003 de \ue003 Na Cl \ue003 (1M) \ue003 (referência) \ue003 e \ue003 NaCl(1M) \ue003 + \ue003 2% \ue003 de \ue003 H 2 SO 4 . \ue003 Os \ue003 resultados \ue003 most ram \ue003 uma \ue003 redução \ue003 progressiva \ue003 da \ue003 mass a \ue003 dos \ue003 CP \ue003 (10 \ue003 x \ue003 20 \ue003 cm, \ue003 7,5 \ue003 x \ue003 15 \ue003 cm) \ue003 e, \ue003 conseqüe nteme nte, \ue003 a \ue003 redução \ue003 da \ue003 resistência \ue003 mecânica \ue003 e \ue003 o \ue003 aumento \ue003 da \ue003 porosidade, \ue003 para \ue003 a \ue003 solução \ue003 contendo \ue003 ácido \ue003 sulfúri co. \ue003 Para \ue003 os \ue003 CP \ue003 expostos \ue003 apenas \ue003 à \ue003 solução \ue003 de \ue003 NaCl , \ue003 há \ue003 um \ue003 ganho \ue003 na \ue003 resistênc ia, \ue003 explicado \ue003 por \ue003 pequenas \ue003 curas \ue003 durante \ue003 os \ue003 ensaios \ue003 e \ue003 a \ue003 ida de \ue003 do \ue003 mesmo. \ue003 Os \ue003 ensaios \ue003 de \ue003 Microscopia \ue003 Eletrônica \ue003 de \ue003 Varredura \ue003 (MEV) \ue003 mostram \ue003 a \ue003 alteração \ue003 microsestr utural \ue003 do \ue003 material, \ue003 com \ue003 incr emento \ue003 da \ue003 porosidade \ue003 e \ue003 precipitação \ue003 significativa \ue003 de \ue003 g esso \ue003 nas \ue003 camadas \ue003 mais \ue003 superficiais. \ue003 Palavra \u2010 Chave: \ue003 durabilidade, \ue003 ambiente \ue003 indu strial, \ue003 ataque \ue003 ácido \ue003\ue003 \ue003 Abstract \ue003 \ue003 The \ue003 reinforced \ue003 concrete \ue003 structures \ue003 under \ue003 the \ue003 influence \ue003 of \ue003 industrial \ue003 environments \ue003 can \ue003 be \ue003 subjected \ue003 to \ue003 the \ue003 simultaneous \ue003 action \ue003 of \ue003 chloride \ue003 ions \ue003 and \ue003 aci d \ue003 substances, \ue003 which \ue003 pro m o te \ue003 the \ue003 pH \ue003 reduct ion \ue003 at \ue003 the \ue003 reinforcement \ue003 surroundin gs \ue003 and \ue003 the \ue003 cementitious \ue003 matrix \ue003 dissolution. \ue003 This \ue003 work \ue003 an alyses \ue003 the \ue003 concrete \ue003 matrix \ue003 be ha vi o r \ue003 under \ue003 this \ue003 kind \ue003 of \ue003 environment. \ue003 Cylindric al \ue003 concrete \ue003 sp ecimens \ue003 were \ue003 cast \ue003 with \ue003 the \ue003 dimensions \ue003 of \ue003 10 \ue003 x \ue003 20 \ue003 cm \ue003 and \ue003 7.5 \ue003 x \ue003 15 \ue003 cm \ue003 with \ue003 w/c \ue003 ratios \ue003 of \ue003 0.3, \ue003 0.4 \ue003 and \ue003 0.5. \ue003 These \ue003 specimens \ue003 were \ue003 subject ed \ue003 to \ue003 wetting \ue003 and \ue003 drying \ue003 cycles \ue003 in \ue003 1 \ue003 molar \ue003 NaCl \ue003 solution \ue003 (reference) \ue003 and \ue003 1 \ue003 molar \ue003 NaCl \ue003 solution \ue003 with \ue003 2% \ue003 of \ue003 H 2 SO 4 . \ue003 Th e \ue003 results \ue003 show \ue003 a \ue003 progressive \ue003 decrease \ue003 of \ue003 specimens \ue003 mass \ue003 and \ue003 on \ue003 compressive \ue003 strength \ue003 and \ue003 porosity \ue003 increase \ue003 for \ue003 sulfu ric \ue003 acid \ue003 solution \ue003 media. \ue003 For \ue003 the \ue003 spec imens \ue003 subjected \ue003 only \ue003 for \ue003 NaCl \ue003 solution, \ue003 ther e \ue003 is \ue003 a \ue003 compres sive \ue003 strength \ue003 inc rease, \ue003 which \ue003 can \ue003 be \ue003 explained \ue003 by \ue003 short \ue003 curing \ue003 periods \ue003 du r ing \ue003 the \ue003 tests \ue003 and \ue003 the \ue003 increasing \ue003 age \ue003 of \ue003 the \ue003 specimens. \ue003 The \ue003 scanning \ue003 electron \ue003 microscopy \ue003 (SEM) \ue003 tests \ue003 show \ue003 the \ue003 material \ue003 microstru cture \ue003 changes, \ue003 with \ue003 an \ue003 increase \ue003 of \ue003 materials \ue003 porosity \ue003 and \ue003 a \ue003 significant \ue003 precipitation \ue003 of \ue003 gypsum \ue003 at \ue003 outer \ue003 layers. \ue003 Keywords: \ue003 durabil ity, \ue003 industrial \ue003 environment, \ue003 acid \ue003 attack \ue003 \ue003 \ue003 IX \ue003 Congreso \ue003 Internaci onal \ue003 sobre \ue003 Patología \ue003 y \ue003 Recuperación \ue003 de \ue003 Estructuras \ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 IX \ue003 Internationa l \ue003 Congress \ue003 on \ue003 Pathology \ue003 and \ue003 Repair \ue003 of \ue003 Structures \ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 João \ue003 Pesso a \u2010 PB \ue003 (Brasil ), \ue003 2 \ue003 a \ue003 5 \ue003 de \ue003 junho \ue003 de \ue003 2013 \ue003 \ue003 Anais \ue003 do \ue003 IX \ue003 Congresso \ue003 Internacional \ue003 sobre \ue003 Patolog ia \ue003 e \ue003 Recup eraç ão \ue003 de \ue003 Estruturas \ue003 \u2013 \ue003 CINPAR \ue003 2013 \ue003 1 \ue003 Introdução \ue003 Estrutur as \ue003 de \ue003 concreto \ue003 apresentam \ue003 comportamentos \ue003 variados \ue003 em \ue003 função \ue003 de \ue003 suas \ue003 características \ue003 iniciais \ue003 e \ue003 do \ue003 ambiente \ue003 ao \ue003 qual \ue003 estão \ue003 submetidos \ue003 [1 \u2010 3]. \ue003 Ações \ue003 de \ue003 degradação \ue003 química \ue003 no \ue003 concreto \ue003 são \ue003 de \ue003 difíceis \ue003 analises, \ue003 tendo \ue003 em \ue003 vista \ue003 a \ue003 gama \ue003 de \ue003 ma teria is, \ue003 o \ue003 complexo \ue003 me ca n i sm o \ue003 de \ue003 hidratação, \ue003 a \ue003 variabilidade \ue003 do \ue003 meio \ue003 com \ue003 o \ue003 tempo \ue003 e \ue003 a \ue003 interação \ue003 da \ue003 matriz \ue003 do \ue003 concreto \ue003 com \ue003 o \ue003 ambiente \ue003 [4]. \ue003\ue003 Ambientes \ue003 industriais \ue003 [5], \ue003 a \ue003 ação \ue003 do \ue003 ambiente \ue003 através \ue003 de \ue003 elementos \ue003 como \ue003 a \ue003 chuva \ue003 acid a[3], \ue003 metabolismos \ue003 de \ue003 bactérias \ue003 do \ue003 gênero \ue003 Desulf ovibrio \ue003 e \ue003 Desulfotomaculum \ue003 [3, \ue003 6], \ue003 oxidação \ue003 de \ue003 minerais \ue003 sulfetos \ue003 que \ue003 geram \ue003 acido \ue003 sulfúrico \ue003 [3 ], \ue003 a \ue003 presença \ue003 de \ue003 sulfa tos \ue003 (SO 4 \u2010 2 ) \ue003 na \ue003 água \ue003 do \ue003 mar \ue003 e \ue003 no \ue003 solo \ue003 [2 \u2010 5] \ue003 e \ue003 a \ue003 decomposição \ue003 de \ue003 matéri as \ue003 org ân ic as \ue003 que \ue003 no \ue003 processo \ue003 [3] \ue003 le vam \ue003 a \ue003 formaç ão \ue003 de \ue003 agentes \ue003 agressivos \ue003 apr esenta \ue003 uma \ue003 potencial \ue003 agressividade \ue003 para \ue003 a \ue003 matr i z \ue003 do \ue003 concreto \ue003 [3]. \ue003 Produtos \ue003 constituídos \ue003 de \ue003 Ci me nt o \ue003 Por tl a n d \ue003 não \ue003 apresentam \ue003 boa \ue003 resistência \ue003 frente \ue003 a \ue003 ambientes \ue003 ácidos, \ue003 explicado \ue003 pelo \ue003 um \ue003 elevado \ue003 pH \ue003 dos \ue003 componentes \ue003 hidratados \ue003\ue003 [1,2]. \ue003 Quando \ue003 o \ue003 concreto \ue003 está \ue003 em \ue003 contato \ue003 com \ue003 so luçõe s \ue003 ácidas, \ue003 este s \ue003 compostos \ue003 podem \ue003 se \ue003 dissolver \ue003 a \ue003 uma \ue003 taxa \ue003 influenciada \ue003 por \ue003 variados \ue003 fatores, \ue003 como \ue003 por \ue003 exemplo: \ue003 a \ue003 permeabilidade \ue003 do \ue003 concreto, \ue003 a \ue003 conc ent ração \ue003 e \ue003 o \ue003 tipo \ue003 de \ue003 ácido \ue003 [3,4]. \ue003 O \ue003 mecanismo \ue003 de \ue003 deterioração \ue003 do \ue003 ataque \ue003 por \ue003 sulfatos \ue003 é \ue003 influenciado \ue003 pelo \ue003 cátion \ue003 ( \ue003 Na + , \ue003 K + , \ue003 Mg 2+ \ue003 ou \ue003 H + ) \ue003 associado \ue003 ao \ue003 anion \ue003 em \ue003 questão, \ue003 SO 4 \u2010 2 . \ue003 Isso \ue003 se \ue003 deve \ue003 principalmente \ue003 as \ue003 trocas \ue003 catiônicas \ue003 que \ue003 influenciaram \ue003 no \ue003 produto \ue003 final \ue003 da \ue003 reação \ue003 [2, \ue003 5]. \ue003 O \ue003 processo \ue003 de \ue003 degradação \ue003 com \ue003 ácido \ue003 su lfúric o \ue003 envolve \ue003 ba sicamente \ue003 três \ue003 etap as \ue003 [2,3,7]: \ue003\ue003 I. difusão \ue003 dos \ue003 íons \ue003 agressivos \ue003 para \ue003 o \ue003 inter ior \ue003 do \ue003 concreto, \ue003 sendo \ue003 este \ue003 fenôm eno \ue003 função \ue003 da \ue003 permeabilidade \ue003 e \ue003 da \ue003 difer ença \ue003 de \ue003 concentra ção \ue003 entre \ue003 o \ue003 meio \ue003 e \ue003 o \ue003 material; \ue003\ue003 II. \ue003 dissolução \ue003 da \ue003 mat ri z \ue003 cimenticia \ue003 [2,5], \ue003 com \ue003 reações \ue003 químicas \ue003 entre \ue003 os \ue003 íons \ue003 sulf ato \ue003 e \ue003 os \ue003 constituintes \ue003 hidratados \ue003 do \ue003 cimento \ue003 formando \ue003 espécies \ue003 químicas \ue003 expansivas \ue003 com o \ue003 a \ue003 etringita \ue003 e \ue003 gipsita \ue003 ( \u2265 7 \ue003 e \ue003 2.2 \ue003 veze s \ue003 maio r \ue003 se \ue003 comparado \ue003 a \ue003 condição \ue003 inici al, \ue003 respec tivamente \ue003 [5,6]); \ue003\ue003 III. fissuração \ue003 da \ue003 matriz \ue003 o \ue003 que \ue003 acelera \ue003 o \ue003 processo \ue003 de \ue003 deterioração, \ue003 resultando \ue003 em \ue003 perda \ue003 de \ue003 resistência \ue003 e \ue003 desintegração. \ue003\ue003 O \ue003 ataque \ue003 ácid o \ue003 se \ue003 processa \ue003 de \ue003 fora \ue003 para \ue003 dentro \ue003 constituind o \ue003 uma \ue003 frente \ue003 de \ue003 red ução \ue003 de \ue003 pH \ue003 no \ue003 entorno \ue003 [2,3,8]. \ue003 O \ue003 efeito \ue003 do \ue003 ácido \ue003 sulfúri co \ue003 no \ue003 concreto \ue003 é \ue003 mais \ue003 preju dicial \ue003 do \ue003 que \ue003 o \ue003 ataque \ue003 por \ue003 outros \ue003 íons \ue003 sulf ato, \ue003 devido \ue003 ao \ue003 efeito \ue003 de \ue003 dissolução \ue003 causada \ue003 pelo s \ue003 íons \ue003 de \ue003 hidrogênio \ue003 [5]. \ue003 O \ue003 principal \ue003 produto \ue003 for mado \ue003 no \ue003 ataque \ue003 por \ue003 acido \ue003 sulf úri co \ue003 é \ue003 o \ue003 gesso, \ue003 devido \ue003 ao \ue003 baixo \ue003 pH \ue003 do \ue003 meio . \ue003 A \ue003 etringita, \ue003 produto \ue003 frequentemente \ue003 visto \ue003 neste \ue003 tipo \ue003 de \ue003 ataque, \ue003 não \ue003 é \ue003 formada \ue003 pois \ue003 não \ue003 apresenta \ue003 estabilida de \ue003 em \ue003 pH \ue003 abaixo \ue003 de \ue003 dez \ue003 [9]. \ue003 O \ue003 fenômeno \ue003 de \ue003 degradação \ue003 no \ue003 co ncreto \ue003 é \ue003 influenciado \ue003 pela \ue003 concentração \ue003 dos \ue003 íons \ue003 sulfatos, \ue003 pelo \ue003 pH \ue003 do \ue003 meio, \ue003\ue003 pelo \ue003 tipo \ue003 de \ue003 agrega do \ue003 empregado, \ue003 pela \ue003 áre a \ue003 de \ue003 contato, \ue003 pelo \ue003 pe ríodo \ue003 de \ue003 exposição, \ue003 pela \ue003 composição \ue003 qu ímica \ue003 do \ue003 cimento \ue003 e \ue003 a \ue003 permeabilidade \ue003 inicial \ue003 do \ue003 concreto \ue003 [6,8]. \ue003 O \ue003 estudo \ue003 de \ue003 concretos \ue003 em \ue003 amb ien tes \ue003 com \ue003 pres ença \ue003 de \ue003 acido \ue003 sulfú rico \ue003 e \ue003 cloretos \ue003 é \ue003 explicado \ue003 pela \ue003 disposição \ue003 do \ue003 concreto \ue003 em \ue003 ambientes \ue003 industriais \ue003 específicos, \ue003 como \ue003 é \ue003 o \ue003 caso \ue003 de \ue003 indústrias \ue003 de \ue003 fabricação \ue003 de \ue003 cloro, \ue003 onde \ue003 esses \ue003 dois \ue003 elementos \ue003 se \ue003 fazem \ue003 presentes. \ue003 É \ue003 nesse \ue003 ambiente \ue003 que \ue003 o \ue003 presente \ue003 trabalho \ue003 se \ue003 insere. \ue003\ue003 \ue003 IX \ue003 Congreso \ue003 Internaci onal \ue003 sobre \ue003 Patología \ue003 y \ue003 Recuperación \ue003 de \ue003 Estructuras \ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 IX \ue003 Internationa l \ue003 Congress \ue003 on \ue003 Pathology \ue003 and \ue003 Repair \ue003 of \ue003 Structures \ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 João \ue003 Pesso a \u2010 PB \ue003 (Brasil ), \ue003 2 \ue003 a \ue003 5 \ue003 de \ue003 junho \ue003 de \ue003 2013 \ue003 \ue003 Anais \ue003 do \ue003 IX \ue003 Congresso \ue003 Internacional \ue003 sobre \ue003 Patolog ia \ue003 e \ue003 Recup eraç ão \ue003 de \ue003 Estruturas \ue003 \u2013 \ue003 CINPAR \ue003 2013 \ue003 2 \ue003 Metodologia \ue003 2.1 \ue003\ue003 Materiais \ue003 e \ue003 confecção \ue003 dos \ue003 corpos \ue003 de \ue003 prova \ue003 Os \ue003 corpos \ue003 de \ue003 prova \ue003 foram \ue003 confeccionados \ue003 com \ue003 os \ue003 seguintes \ue003 agregados: \ue003 areia \ue003 media \ue003 lava \ue003 de \ue003 cav a \ue003 e \ue003 brita \ue003 granítica, \ue003 detalhadas \ue003 na \ue003 tabela \ue003 1. \ue003 O \ue003 aglomerante \ue003 utiliz ado \ue003 foi \ue003 o \ue003 Cimento \ue003 Portland \ue003 V \ue003 \u2013 \ue003 ARI, \ue003 cujas \ue003 propri edades \ue003 químicas \ue003 estão \ue003 na \ue003 Tabela \ue003 2. \ue003 De \ue003 modo \ue003 a \ue003 obter \ue003 uma \ue003 trabalhabilidade \ue003 adequada \ue003 as \ue003 mold agens \ue003 dos \ue003 corpos \ue003 de \ue003 prova \ue003 cilíndricos \ue003 (7,5 \ue003 x \ue003 15cm \ue003 e \ue003 10 \ue003 x \ue003 20cm), \ue003 foi \ue003 necessário \ue003 o \ue003 uso \ue003 de \ue003 aditivos \ue003 plastificantes \ue003 e \ue003 super \u2010 plastifican te \ue003 de \ue003 base \ue003 sulfo nada \ue003 aniônica \ue003 de \ue003 cad eia \ue003 longa. \ue003 Tabela 1 - Característic as físicas dos agregados M. \ue003\ue003 Es . \ue003 Real \ue003 g/cm³ \ue003 M. \ue003 Unitária \ue003 g/cm³ \ue003 Modulo \ue003 de \ue003 Finura \ue003 % \ue003 Dimensão \ue003 Máxima \ue003 Característica \ue003 mm \ue003 Agregado \ue003 Miúdo \ue003 2,58 \ue003 1, 71 \ue003 3, 0 3 \ue003 4,8 \ue003 Agregado \ue003 Graúdo \ue003 2, 6 3 \ue003 1, 20 \ue003 6, 9 5 \ue003 3\u201d/4 \ue003 Tabela \ue003 2 \ue003 \u2013 \ue003 Características \ue003 qu ím ic as \ue003 do \ue003 ciment o \ue003 Item \ue003 SO 3 \ue003 SiO 2 \ue003 Al 2 O 3 \ue003 Fe 2 O 3 \ue003 CaO \ue003 Mg O \ue003 PPC \ue003 Outr os \ue003 (%) \ue003 0, 96 \ue003 18,56 \ue003 5,06 \ue003 2,27 \ue003 60,59 \ue003 2,58 \ue003 3, 25 \ue003 6,73 \ue003 A \ue003 tabela \ue003 3 \ue003 mostr a \ue003 as \ue003 dosagens \ue003 utilizadas \ue003 neste \ue003 trabalho. \ue003 As \ue003 mesmas \ue003 contemplam \ue003 uma \ue003 gama \ue003 representativa \ue003 de \ue003 fatores \ue003 água/aglomerante, \ue003 propiciando \ue003 uma \ue003 variabilida de \ue003 considerável \ue003 na \ue003 porosidade \ue003 do \ue003 material. \ue003 Após \ue003 a \ue003 moldagem \ue003 de \ue003 corpos \ue003 dos \ue003 prova, \ue003 os \ue003 mesmos \ue003 foram \ue003 desmoldad os \ue003 após \ue003 24 \ue003 horas \ue003 e \ue003 curados \ue003 em \ue003 imersão \ue003 total \ue003 em \ue003 água \ue003 por \ue003 sete \ue003 dias, \ue003 seguindo \u2010 se \ue003 por \ue003 mais \ue003 56 \ue003 dias \ue003 em \ue003 ambiente \ue003 de \ue003 laboratório. \ue003 Após \ue003 esse \ue003 perí odo, \ue003 os \ue003 mesmos \ue003 foram \ue003 disponibil izados \ue003 para \ue003 os \ue003 ensaios \ue003 específicos. \ue003 Tabela \ue003 3 \ue003 \u2013 \ue003 Dosagens \ue003 empregadas \ue003 em \ue003 mass a \ue003 Dosagem \ue003 Cimento \ue003 Metacaulim Areia \ue003 Brita \ue003 Água \ue003 ARI30 \ue003 0,9 \ue003 0. 1 \ue003 1, 57 \ue003 1,94 \ue003 0,3 \ue003 ARI40 \ue003 1 \ue003\u2010 \ue003 1,57 \ue003 1,94 \ue003 0, 4 \ue003 ARI50 \ue003 1 \ue003\u2010 \ue003 2,16 \ue003 2,24 \ue003 0, 5 \ue003 2.2 \ue003 Ensaios \ue003 rea lizados \ue003 Os \ue003 ensaios \ue003 de \ue003 resistência \ue003 a \ue003 com pressão \ue003 axial, \ue003 absorção \ue003 total \ue003 e \ue003 perda \ue003 de \ue003 massa \ue003 fo ram \ue003 realizados \ue003 nos \ue003 CP \ue003 confeccionados, \ue003 além \ue003 dos \ue003 ensaios \ue003 de \ue003 caracterização \ue003 dos \ue003 materiais \ue003 empregados. \ue003 Os \ue003 ensaios \ue003 de \ue003 resistência \ue003 à \ue003 compressão \ue003 foram \ue003 realizados \ue003 de \ue003 acordo \ue003 com \ue003 a \ue003 NBR \ue003 7215/96, \ue003 obedecendo \u2010 se \ue003 idades \ue003 de \ue003 ensaio \ue003 de \ue003 56, \ue003 140 \ue003 e \ue003 280 \ue003 dias. \ue003\ue003 Pa ra \ue003 ensaio \ue003 de \ue003 absorção, \ue003 seg uir am \u2010 se \ue003 as \ue003 orientações \ue003 da \ue003 NBR \ue003 9778/05, \ue003 empregando \u2010 se \ue003 três \ue003 corpos \ue003 de \ue003 pr ova \ue003 para \ue003 cada \ue003 condição \ue003 anali sada \ue003 no \ue003 trabalho. \ue003 A \ue003 idade \ue003 dos \ue003 CP\u2019s \ue003 foi \ue003 análoga \ue003 às \ue003 do \ue003 ensaio \ue003 de \ue003 resistência. \ue003 IX \ue003 Congreso \ue003 Internaci onal \ue003 sobre \ue003 Patología \ue003 y \ue003 Recuperación \ue003 de \ue003 Estructuras \ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 IX \ue003 Internationa l \ue003 Congress \ue003 on \ue003 Pathology \ue003 and \ue003 Repair \ue003 of \ue003 Structures \ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 João \ue003 Pesso a \u2010 PB \ue003 (Brasil ), \ue003 2 \ue003 a \ue003 5 \ue003 de \ue003 junho \ue003 de \ue003 2013 \ue003 \ue003 Anais \ue003 do \ue003 IX \ue003 Congresso \ue003 Internacional \ue003 sobre \ue003 Patolog ia \ue003 e \ue003 Recup eraç ão \ue003 de \ue003 Estruturas \ue003 \u2013 \ue003 CINPAR \ue003 2013 \ue003 Os \ue003 ensaios \ue003 de \ue003 perda \ue003 de \ue003 mass a \ue003 cons istiram \ue003 em \ue003 ciclos \ue003 semanais \ue003 de \ue003 imersão \ue003 e \ue003 secagem, \ue003 na \ue003 proporção \ue003 de \ue003 quatro \ue003 dias \ue003 para \ue003 imersã o \ue003 total \ue003 e \ue003 três \ue003 dias \ue003 para \ue003 secagem \ue003 em \ue003 am biente \ue003 de \ue003 laboratório. \ue003 No \ue003 inicio \ue003 de \ue003 cada \ue003 ciclo, \ue003 os \ue003 corpos \ue003 de \ue003 prova \ue003 eram \ue003 limpos, \ue003 com \ue003 o \ue003 objeti vo \ue003 da \ue003 retida \ue003 do \ue003 material \ue003 aderente \ue003 à \ue003 superfície, \ue003 fruto \ue003 do \ue003 ataque \ue003 ácido. \ue003 Como \ue003 objetivo \ue003 de \ue003 minimizar \ue003 a \ue003 variação \ue003 de \ue003 massa \ue003 dos \ue003 CP \ue003 devido \ue003 a \ue003 difere ntes \ue003 condições \ue003 climáticas, \ue003 os \ue003 mes mos \ue003 foram \ue003 pesados \ue003 apos \ue003 os \ue003 dias \ue003 de \ue003 imersão. \ue003 Estes \ue003 procedimentos \ue003 tiveram \ue003 como \ue003 ponto \ue003 de \ue003 partida \ue003 a \ue003 conclusão \ue003 da \ue003 cu ra. \ue003\ue003 As \ue003 soluções \ue003 empregadas \ue003 foram \ue003 a \ue003 de \ue003 referência \ue003 de \ue003 NaCl \ue003 (1M) \ue003 e \ue003\ue003 a \ue003 de \ue003 NaCl \ue003 (1M) \ue003 com \ue003 2% \ue003 de \ue003 acido \ue003 sulfúrico \u2010 . \ue003 O \ue003 pH \ue003 da \ue003 solução \ue003 fo i \ue003 monitorado \ue003 sem anal ment e, \ue003 com \ue003 o \ue003 objetivo \ue003 de \ue003 evitar \ue003 su a \ue003 variação \ue003 acima \ue003 de \ue003 , \ue003 no \ue003 máximo, \ue003 uma \ue003 unidade. \ue003 Quando \ue003 a \ue003 variação \ue003 do \ue003 pH \ue003 era \ue003 super ior \ue003 a \ue003 1, \ue003 a \ue003 soluçã o \ue003 era \ue003 substituída. \ue003 Após \ue003 14 \ue003 ciclos \ue003 (154 \ue003 dias) \ue003 e \ue003 32 \ue003 ciclos \ue003 (280dias ) \ue003 em \ue003 imersão \ue003 e \ue003 secagem, \ue003 CP \ue003 foram \ue003 subm etid os \ue003 a \ue003 medida \ue003 do \ue003 diâmetro \ue003 da \ue003 seção \ue003 tr ansv ersa l \ue003 apos \ue003 limpeza \ue003 su perficial, \ue003 com \ue003 o \ue003 uso \ue003 de \ue003 um \ue003 paquímetro, \ue003 a \ue003 ensaios \ue003 de \ue003 resistênc ia \ue003 e \ue003 absorção, \ue003 confor me \ue003 proce dimento \ue003 já \ue003 descrito \ue003 acima. \ue003\ue003 3 \ue003 Resultados \ue003 e \ue003 Discussões \ue003 3.1 \ue003\ue003 Res istência \ue003 mecâni ca \ue003\ue003 A \ue003 Figura \ue003 1 \ue003 mostra \ue003 os \ue003 resultados \ue003 de \ue003 resistência \ue003 mecânica \ue003 após \ue003 os \ue003 ensaio s \ue003 relatados \ue003 no \ue003 item \ue003 2.2. \ue003 Percebe \u2010 se \ue003 claram ente \ue003 uma \ue003 queda \ue003 acentuada \ue003 na \ue003 resi stência \ue003 dos \ue003 CP \ue003 para \ue003 a \ue003 solução \ue003 contendo \ue003 acido \ue003 sulfúrico. \ue003 Para \ue003 a \ue003 solução \ue003 de \ue003 referenc ia, \ue003 observa \u2010 se \ue003 um \ue003 ganh o \ue003 na \ue003 resistênci a \ue003 propiciado \ue003 pelas \ue003 pequenas \ue003 curas \ue003 e \ue003 a \ue003 hidratação \ue003 progress iva \ue003 do \ue003 ag lomera nte . \ue003\ue003 Figura \ue003 1 \ue003\u2010\ue003 Comportamento \ue003 da \ue003 resistê ncia \ue003 mecânica \ue003 ao \ue003 longo \ue003 dos \ue003 ensaios \ue003 Comparando \ue003 com \ue003 a \ue003 solução \ue003 de \ue003 referência, \ue003 os \ue003 corpos \ue003 de \ue003 prova \ue003 a presentaram \ue003 redução \ue003 máxima \ue003 na \ue003 seção \ue003 transversal \ue003 entorno \ue003 de \ue003 1,5% \ue003 (ARI50). \ue003 Os \ue003 cálculos \ue003 de \ue003 resis tên cia \ue003 le va r a m \ue003 em \ue003 consideração \ue003 este \ue003 parâmetro. \ue003 Já \ue003 a \ue003 perda \ue003 de \ue003 resistência \ue003 máxim a \ue003 ficou \ue003 em \ue003 torno \ue003 de \ue003 15% \ue003 para \ue003 ARI50 \ue003 na \ue003 solução \ue003 deletéria. \ue003 Por \ue003 fim, \ue003 conside ra \u2010 se \ue003 uma \ue003 perda \ue003 de \ue003 resistência \ue003 considerável \ue003 tendo \ue003 em \ue003 vista \ue003 o \ue003 curto \ue003 tempo \ue003 de \ue003 ensaio \ue003 e \ue003 uma \ue003 redução \ue003 gradativa \ue003 da \ue003 seção \ue003 transversal. \ue003 IX \ue003 Congreso \ue003 Internaci onal \ue003 sobre \ue003 Patología \ue003 y \ue003 Recuperación \ue003 de \ue003 Estructuras \ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 IX \ue003 Internationa l \ue003 Congress \ue003 on \ue003 Pathology \ue003 and \ue003 Repair \ue003 of \ue003 Structures \ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 João \ue003 Pesso a \u2010 PB \ue003 (Brasil ), \ue003 2 \ue003 a \ue003 5 \ue003 de \ue003 junho \ue003 de \ue003 2013 \ue003 \ue003 Anais \ue003 do \ue003 IX \ue003 Congresso \ue003 Internacional \ue003 sobre \ue003 Patolog ia \ue003 e \ue003 Recup eraç ão \ue003 de \ue003 Estruturas \ue003 \u2013 \ue003 CINPAR \ue003 2013 \ue003 3.2 \ue003 Absorçã o \ue003 total \ue003 A \ue003 Figu r a \ue003 2 \ue003 mostra \ue003 os \ue003 res ultados \ue003 pra \ue003 absor ção \ue003 total \ue003 dos \ue003 corpos \ue003 de \ue003 prova \ue003 su bmet ido s \ue003 aos \ue003 ciclos \ue003 de \ue003 imersão \ue003 e \ue003 secagem \ue003 nas \ue003 soluções \ue003 estudadas. \ue003 Esse \ue003 ensaio \ue003 tev e \ue003 como \ue003 objetivo \ue003 analisar \ue003 o \ue003 au mento \ue003 de \ue003 porosidade \ue003 do \ue003 material \ue003 com \ue003 a \ue003 agressividade \ue003 do \ue003 meio \ue003 e \ue003 o \ue003 tempo \ue003 de \ue003 exposição. \ue003 Figu r a \ue003 2 \ue003\u2010\ue003 Absorção \ue003 dos \ue003 CP's \ue003 Considerando \ue003 os \ue003 resultados \ue003 aqui \ue003 apresentados, \ue003 observa \u2010 se, \ue003 para \ue003 uma \ue003 mesma \ue003 soluçã o, \ue003 uma \ue003 perd a \ue003 na \ue003 absorção \ue003 com \ue003 o \ue003 tempo, \ue003 explicado \ue003 pelo \ue003 refinamento \ue003 dos \ue003 poros \ue003 com \ue003 a \ue003 idade. \ue003 Comp arando \u2010 se \ue003 soluções \ue003 diferentes, \ue003 percebe \u2010 se \ue003 um \ue003 ganho \ue003 na \ue003 taxa \ue003 de \ue003 absorção, \ue003 ou \ue003 seja, \ue003 há \ue003 uma \ue003 maior \ue003 facilidade \ue003 de \ue003 transporte \ue003 de \ue003 massa \ue003 para \ue003 o \ue003 interior \ue003 do \ue003 concreto. \ue003 Esse \ue003 ganho \ue003 máximo \ue003 fi cou \ue003 em \ue003 torno \ue003 de \ue003 1%, \ue003 um \ue003 valor \ue003 que \ue003 pode \ue003 acelerar \ue003 de \ue003 forma \ue003 significativa \ue003 a \ue003 degra dação \ue003 do \ue003 materi al . \ue003 A \ue003 Fig u ra \ue003 3 \ue003 mos tra \ue003 os \ue003 resultados \ue003 de \ue003 índice \ue003 de \ue003 vazios \ue003 do \ue003 material \ue003 em \ue003 que stão, \ue003 obtidos \ue003 atr avés \ue003 do \ue003 mes mo \ue003 ensaio \ue003 de \ue003 absorção. \ue003 Figura \ue003 3 \ue003\u2010\ue003 Índice \ue003 de \ue003 vazios \ue003 dos \ue003 CP`s \ue003 \ue003 Os \ue003 resultados \ue003 do \ue003 índice \ue003 de \ue003 vazios \ue003 seguem \ue003 o \ue003 mesmo \ue003 racio cínio \ue003 da \ue003 absorção , \ue003 comparando \ue003 as \ue003 soluções \ue003 e \ue003 os \ue003 diversos \ue003 materiais \ue003 empregados, \ue003 obs ervo u \u2010 se \ue003 que \ue003 os \ue003 CP\u2019s \ue003 ARI50 \ue003 apresentaram \ue003 o \ue003 maior \ue003 aumento, \ue003 entorno \ue003 de \ue003 8%. \ue003 Para \ue003 demais \ue003 resultados \ue003 do \ue003 ensaio \ue003 de \ue003 absorção, \ue003 observa \u2010 se \ue003 um \ue003 queda \ue003 grad ati va \ue003 na \ue003 massa \ue003 especifica \ue003 real, \ue003 explica da \ue003 pela \ue003 perda \ue003 de \ue003 ma ssa \ue003 (ver \ue003 item \ue003 3.3). \ue003 IX \ue003 Congreso \ue003 Internaci onal \ue003 sobre \ue003 Patología \ue003 y \ue003 Recuperación \ue003 de \ue003 Estructuras \ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 IX \ue003 Internationa l \ue003 Congress \ue003 on \ue003 Pathology \ue003 and \ue003 Repair \ue003 of \ue003 Structures \ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 João \ue003 Pesso a \u2010 PB \ue003 (Brasil ), \ue003 2 \ue003 a \ue003 5 \ue003 de \ue003 junho \ue003 de \ue003 2013 \ue003 \ue003 Anais \ue003 do \ue003 IX \ue003 Congresso \ue003 Internacional \ue003 sobre \ue003 Patolog ia \ue003 e \ue003 Recup eraç ão \ue003 de \ue003 Estruturas \ue003 \u2013 \ue003 CINPAR \ue003 2013 \ue003 3.3 \ue003 Perda \ue003 de \ue003 massa \ue003 A \ue003 Figura \ue003 4 \ue003 mostra \ue003 os \ue003 resultados \ue003 de \ue003 pe rd a \ue003 de \ue003 massa \ue003 dos \ue003 CP \ue003 com \ue003 a \ue003 idade. \ue003 O \ue003 objetivo \ue003 deste \ue003 ensaio \ue003 é \ue003 acompanhar \ue003 a \ue003 dissoluç ão \ue003 do \ue003 mate rial . \ue003 Figura \ue003 4 \ue003\u2010\ue003 Perda \ue003 de \ue003 massa \ue003 dos \ue003 CP \u2019s \ue003 Observa \u2010 se \ue003 o \ue003 decréscimo \ue003 da \ue003 massa \ue003 dos \ue003 corpos \ue003 de \ue003 prova \ue003 submetidos \ue003 às \ue003 so luçõ es \ue003 agressiv as \ue003 durante \ue003 o \ue003 período \ue003 de \ue003 exposição \ue003 em \ue003 questão. \ue003 Esse \ue003 decréscimo \ue003 ocorre \ue003 de \ue003 modo \ue003 gradual \ue003 e \ue003 aproximadamente \ue003 linear, \ue003 sendo \ue003 mais \ue003 acentuado \ue003 para \ue003 ARI \ue003 50. \ue003 A \ue003 Fig u r as \ue003 5 \ue003 mo str a \ue003 a \ue003 aparência \ue003 do \ue003 CP´s \ue003 ARI \ue003 50, \ue003 após \ue003 a \ue003 realizados \ue003 ensaios \ue003 . \ue003 Figura \ue003 5 \ue003 \u2013 \ue003 A \ue003 esquerda \ue003 os \ue003 CP\u2019s \ue003 ARI \ue003 50 \ue003 em \ue003 solu ção \ue003 de \ue003 NaCl \ue003 e \ue003 a \ue003 direita \ue003 os \ue003 CP\u2019s \ue003 ARI \ue003 50 \ue003 em \ue003 solução \ue003 de \ue003 NaCl \ue003 + \ue003 2% \ue003 de \ue003 H2SO4 \ue003 3.4 \ue003\ue003 Análise \ue003 da \ue003 micro \u2010 estrutura \ue003 do \ue003 concr et o \ue003 atacado \ue003 Os \ue003 resultados \ue003 de \ue003 microscopia \ue003 eletrônica \ue003 de \ue003 varredura \ue003 indicam \ue003 a \ue003 formação \ue003 de \ue003 gipsita \ue003 na \ue003 superfície \ue003 do \ue003 material, \ue003 resultante \ue003 da \ue003 conversã o \ue003 de \ue003 compostos \ue003 à \ue003 base \ue003 de \ue003 cálcio \ue003 em \ue003 sulfato \ue003 de \ue003 cálcio \ue003 (Figura \ue003 6). \ue003 IX \ue003 Congreso \ue003 Internaci onal \ue003 sobre \ue003 Patología \ue003 y \ue003 Recuperación \ue003 de \ue003 Estructuras \ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 IX \ue003 Internationa l \ue003 Congress \ue003 on \ue003 Pathology \ue003 and \ue003 Repair \ue003 of \ue003 Structures \ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 João \ue003 Pesso a \u2010 PB \ue003 (Brasil ), \ue003 2 \ue003 a \ue003 5 \ue003 de \ue003 junho \ue003 de \ue003 2013 \ue003 \ue003 Anais \ue003 do \ue003 IX \ue003 Congresso \ue003 Internacional \ue003 sobre \ue003 Patolog ia \ue003 e \ue003 Recup eraç ão \ue003 de \ue003 Estruturas \ue003 \u2013 \ue003 CINPAR \ue003 2013 \ue003 Esses \ue003 resultados \ue003 foram \ue003 confirmados \ue003 pelos \ue003 ensaios \ue003 de \ue003 difração \ue003 de \ue003 raios \ue003 X \ue003 realizados \ue003 em \ue003 camadas \ue003 da \ue003 superfície \ue003 para \ue003 o \ue003 interior \ue003 do \ue003 concreto. \ue003 Figura \ue003 6 \ue003 \u2013 \ue003 Formação \ue003 de \ue003 gip sita \ue003 na \ue003 superf ície \ue003 do \ue003 concre to \ue003 atacado. \ue003 As \ue003 principais \ue003 alterações \ue003 micro \u2010 estruturai s \ue003 sofridas \ue003 pel a \ue003 ma tri z \ue003 de \ue003 concreto \ue003 estão \ue003 re l ac i on a das \ue003 à \ue003 formação \ue003 de \ue003 gipsita \ue003 e \ue003 o \ue003 aumento \ue003 da \ue003 porosidade \ue003 do \ue003 concreto, \ue003 o \ue003 que \ue003 se \ue003 traduz \ue003 em \ue003 aumento \ue003 do s \ue003 índices \ue003 de \ue003 absorção, \ue003 queda \ue003 da \ue003 resistência \ue003 mecânica \ue003 e \ue003 perda \ue003 progressiva \ue003 da \ue003 pasta \ue003 hidratada. \ue003 4 \ue003 Conclusões \ue003\ue003 O \ue003 desempenho \ue003 de \ue003 concretos \ue003 em \ue003 ambientes \ue003 com \ue003 a \ue003 presença \ue003 de \ue003 ácido \ue003 sulfúrico \ue003 é \ue003 fortemente \ue003 influenciado \ue003 pelas \ue003 características \ue003 iniciais \ue003 do \ue003 material, \ue003 o \ue003 tempo \ue003 de \ue003 exposição \ue003 ao \ue003 meio \ue003 e \ue003 o \ue003 pH \ue003 da \ue003 solução. \ue003 Ataque \ue003 de \ue003 ácido \ue003 sulfú rico \ue003 provoca \ue003 perda \ue003 progressiva \ue003 de \ue003 mas sa, \ue003 dissolução \ue003 dos \ue003 produtos \ue003 hidratados \ue003 da \ue003 pa sta, \ue003 au me nto \ue003 g radativo \ue003 da \ue003 porosidade, \ue003 formação \ue003 de \ue003 gipsita \ue003 e \ue003 tem \ue003 como \ue003 consequencia \ue003 a \ue003 redução \ue003 progressiva \ue003 da \ue003 resistênc ia \ue003 mecânica \ue003 do \ue003 material. \ue003\ue003 Os \ue003 concretos \ue003 mais \ue003 poros os \ue003 facilitam \ue003 o \ue003 acesso \ue003 das \ue003 substâncias \ue003 agressi vas \ue003 ao \ue003 seu \ue003 interior \ue003 e \ue003 apresentam \ue003 tendências \ue003 mais \ue003 acentuadas \ue003 de \ue003 perdas \ue003 de \ue003 massa \ue003 e \ue003 resistênc ia. \ue003 Com \ue003 o \ue003 aumento \ue003 do \ue003 tempo \ue003 de \ue003 exposição \ue003 maior \ue003 a \ue003 ação \ue003 deletéria \ue003 do \ue003 meio \ue003 agressivo. \ue003 5 \ue003\ue003 Agradecimentos \ue003 Agradecemos \ue003 a \ue003 Conselho \ue003 Na cional \ue003 de \ue003 Desenvolvime nto \ue003 Científico \ue003 e \ue003 Tecnol óg ico \ue003 (CNPq) \ue003 pelo \ue003 financiamento \ue003 da \ue003 pesquisa \ue003 e \ue003 bo lsa \ue003 concedida. \ue003 6 \ue003\ue003 Referências \ue003 [1] DE \ue003 BELIE, \ue003 N.; \ue003 et. \ue003 al.. \ue003 Influence \ue003 of \ue003 the \ue003 cement \ue003 ty pe \ue003 on \ue003 the \ue003 resis tance \ue003 of \ue003 concre te \ue003 to \ue003 feed \ue003 acids. \ue003 Cement \ue003 and \ue003 Concre te \ue003 Research, \ue003 v.35, \ue003 p. \ue003 2333 \u2010 2339, \ue003 2005. \ue003 [2] MEHTA, \ue003 P. \ue003 K.; \ue003 MONTEI RO, \ue003 P. \ue003 J. \ue003 M. \ue003 Concreto: \ue003 Microestrutura, \ue003 propriedades \ue003 e \ue003 materiais. \ue003 Tradutora \ue003 Cristina \ue003 Borba. \ue003 São \ue003 Paulo: \ue003 Ibracon, \ue003 2008, \ue003 p. \ue003 121 \u2010 123, \ue003 p. \ue003 156, \ue003 p. \ue003 161 \u2010 170. \ue003 IX \ue003 Congreso \ue003 Internaci onal \ue003 sobre \ue003 Patología \ue003 y \ue003 Recuperación \ue003 de \ue003 Estructuras \ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 IX \ue003 Internationa l \ue003 Congress \ue003 on \ue003 Pathology \ue003 and \ue003 Repair \ue003 of \ue003 Structures \ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 \ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003\ue003 João \ue003 Pesso a \u2010 PB \ue003 (Brasil ), \ue003 2 \ue003 a \ue003 5 \ue003 de \ue003 junho \ue003 de \ue003 2013 \ue003 \ue003 Anais \ue003 do \ue003 IX \ue003 Congresso \ue003 Internacional \ue003 sobre \ue003 Patolog ia \ue003 e \ue003 Recup eraç ão \ue003 de \ue003 Estruturas \ue003 \u2013 \ue003 CINPAR \ue003 2013 \ue003 [3] UNDERSTANDING \ue003 CEMEMENT. \ue003 Sulfate \ue003 attack \ue003 in \ue003 concrete \ue003 and \ue003 mortar. \ue003 Ce me nt \ue003 Glossary \ue003 \u2013 \ue003 Microanalys \ue003 consultants, \ue003 2009. \ue003 Disponivel \ue003 em \ue003 \u2010 cement.com/sulfate.html>. \ue003 Acessado \ue003 em \ue003 22 \ue003 de \ue003 fevereiro \ue003 de \ue003 2009. \ue003 [4] BENSTED, \ue003 J.; \ue003 BROUGH, \ue003 A. \ue003 R.; \ue003 PAGE, \ue003 M. \ue003 M. \ue003 Du rability \ue003 of \ue003 concrete \ue003 and \ue003 ceme nt \ue003 composites, \ue003 chapter \ue003 4 \ue003 \u2010\ue003 Chemical \ue003 degradat ion \ue003 of \ue003 concrete. \ue003 Woodhead \ue003 Publishing \ue003 and \ue003 Maney \ue003 Publishing \ue003 on \ue003 behalf \ue003 of \ue003 The \ue003 Institute \ue003 of \ue003 Materials, \ue003 Minerals \ue003 & \ue003 Mining. \ue003 England,2007, \ue003 p. \ue003 89 \u2010 90. \ue003 [5] BASSUONI, \ue003 M. \ue003 T.; \ue003 NEDHI, \ue003 M. \ue003 L . \ue003 Resistance \ue003 of \ue003 self \u2010 consolidating \ue003 concrete \ue003 to \ue003 sulfuric \ue003 acid \ue003 attack \ue003 with \ue003 consecutive \ue003 pH \ue003 reduction. \ue003 Cement \ue003 and \ue003 Conc rete \ue003 Research, \ue003 v.37, \ue003 p. \ue003 1070 \u2010 108 4, \ue003 2007. \ue003 [6] MOTENY, \ue003 J.; \ue003 at \ue003 el . \ue003 Chemical, \ue003 microbiological, \ue003 and \ue003 in \ue003 situ \ue003 test \ue003 methods \ue003 for \ue003 biogenic \ue003 sulfuric \ue003 acid \ue003 corrosion \ue003 of \ue003 concrete, \ue003 Cement \ue003 and \ue003 Concrete \ue003 Research , \ue003 v.30, \ue003 p. \ue003 623 \u2010 634, \ue003 2000. \ue003 [7] FATTUHI, \ue003 N. \ue003 I.; \ue003 HUGHES, \ue003 B. P. \ue003 The \ue003 performance \ue003 of \ue003 cement \ue003 Paste \ue003 and \ue003 concrete \ue003 subjec ted \ue003 to \ue003 acid \ue003 attack. \ue003 Cement \ue003 and \ue003 Concrete \ue003 Research, \ue003 v.18, \ue003 p. \ue003 545 \u2010 553, \ue003 199 8. \ue003 [8] BEDDOE, \ue003 R. \ue003 E.; \ue003 DORNER, \ue003 H. \ue003 W. \ue003 Modelling \ue003 acid \ue003 attack \ue003 on \ue003 concrete : \ue003 Part \ue003 I \ue003 The \ue003 essential \ue003 mecanisms. \ue003 Cement \ue003 and \ue003 Conc rete \ue003 Research, \ue003 v.26, \ue003 p.1717 \u2010 1725 , \ue003 1996. \ue003 [9] ZHOU, \ue003 Q.; \ue003 at \ue003 el. \ue003 The \ue003 role \ue003 of \ue003 pH \ue003 in \ue003 thaumasite \ue003 sulfate \ue003 attack. \ue003 Cement \ue003 and \ue003 Concrete \ue003 Research, \ue003 v.36, \ue003 p. \ue003 160 \u2010 170, \ue003 2006. \ue003 [10] ASSOCIAÇÃO \ue003 BRASIL EI RA \ue003 DE \ue003 NORMAS \ue003 TÉNICAS. \ue003 NBR \ue003 57 38: \ue003 Concretos: \ue003 procedim entos \ue003 para \ue003 moldagem \ue003 e \ue003 cura \ue003 de \ue003 corpos \ue003 de \ue003 prova . \ue003 Rio \ue003 de \ue003 Jan eiro, \ue003 2002 \ue003 [11] ______. \ue003 NBR \ue003 7217: \ue003 Agregados \ue003\u2010 \ue003 Determinação \ue003 da \ue003 composição \ue003 granulométrica . \ue003 Rio \ue003 de \ue003 Janeiro , \ue003 1987. \ue003 [12] ______. \ue003 NBR \ue003 9776: \ue003 Agregados \ue003\u2010 \ue003 Determinação \ue003 da \ue003 mass a \ue003 específica \ue003 de \ue003 agregados \ue003 miúdos \ue003 por \ue003 meio \ue003 do \ue003 frasco \ue003 Chapman. \ue003 Rio \ue003 de \ue003 Janeiro, \ue003 1987. \ue003 [13] ______. \ue003 NBR \ue003 7251: \ue003 Agregado \ue003 em \ue003 estado \ue003 solto \ue003\u2010 \ue003 Determinação \ue003 da \ue003 massa \ue003 unitária. \ue003 Rio \ue003 de \ue003 Janeiro, \ue003 1982. \ue003 [14] ______. \ue003 NBR \ue003 9937: \ue003 Agregados \ue003\u2010\ue003 Determinação \ue003 da \ue003 absorção \ue003 e \ue003 da \ue003 mas sa \ue003 específica \ue003 de \ue003 agregado \ue003 graúdo. \ue003 Rio \ue003 de \ue003 Janeir o, \ue003 1987 . \ue003 [15] ______. \ue003 NBR \ue003 7215: \ue003 Cime nt o \ue003 Portland \ue003\u2010 \ue003 Determinação \ue003 da \ue003 resistência \ue003 à \ue003 compre ssão. \ue003 Rio \ue003 de \ue003 Janeiro, \ue003 1996. \ue003 [16] ______. \ue003 NBR \ue003 9778: \ue003 Argamassa \ue003 e \ue003 concre to \ue003 endurecido \ue003 \u2013 \ue003 Determinação \ue003 da \ue003 absorção \ue003 de \ue003 água \ue003 por \ue003 imersão \ue003 (Índice \ue003 de \ue003 vazios \ue003 e \ue003 massa \ue003 especifica). \ue003 Rio \ue003 de \ue003 Janeiro, \ue003 2005. \ue003\ue003

Estudo do Comportamento de Concretos em Ambiente com a Presença de Ácido Sulfúrico e Cloretos

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