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Title |
Evaluating Early Age Shrinkage Behavior of Ultra High Performance Cementitious Composites (UHPCC) with CSA Expansive Admixture and Shrinkage Reducing Agent
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Keywords |
초고성능 시멘트 복합체 ; 화학수축 ; 자기건조 ; 자기수축 time-zero ; ultra high performance cementitious composites ; chemical shrinkage ; self-desiccation ; autogenous shrinkage ; time-zero |
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Abstract |
In this study, experimental tests of chemical and autogenous shrinkage were performed to evaluate the early age shrinkage behaviors of ultra high performance cementitious composites (UHPCC) with various replacement ratios of silica fume (SF), shrinkage reducing agent (SRA), expansive admixture (EA), and superplasticizer (SP). Starting time of self-desiccation, was analyzed by comparing the setting times and the deviated point of chemical and autogenous shrinkage strains. The test results indicated that both SF and SRA augment the early age chemical shrinkage, whereas SP delays the hydration reaction between cement particles and water, and reduces chemical shrinkage. About 49% of autogenous shrinkage was depleted by synergetic effect of SRA and EA. The hardening of UHPCC was catalyzed by containing EA. Self-desiccation of UHPCC occurred prior to the initial setting due to the high volume fraction of fibers and low water-binder ratio (W/B).
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