抗裂高性能混凝土的制备与性能研究  

Preparation and Performance Study of Cracking Resistance High Performance Concrete

作　　者：王国军 岳伟杰 储洪强[2] WANG Guo-jun;YUE Wei-jie;CHU Hong-qiang(Guangzhou Highway Co.,Ltd.,Guangzhou 510440;Hohai University,Nanjing 211100)

机构地区：[1]广州市高速公路有限公司,广州510440 [2]河海大学,南京211100

出　　处：《广州建筑》2024年第2期75-79,共5页GUANGZHOU ARCHITECTURE

摘　　要：混凝土的开裂问题一直是工程上一道亟待解决的难题。为改善混凝土工作性能,降低水化放热量,增强其抗裂性能,本文通过试验,对不同粉煤灰掺量的混凝土的各项性能进行对比研究,包括力学性能、热学性能和长期性能,比较分析不同粉煤灰掺量下混凝土的各项性能差异。结果表明,随粉煤灰掺量增加,混凝土呈现出强度前期降低后期迅速增长的趋势,当粉煤灰掺量达到50%时,与未掺粉煤灰的试件相比,其7 d抗压强度降低了40.3%,60 d强度较7 d强度增长了53.9%;粉煤灰的加入明显地降低了胶凝体系的放热速率,粉煤灰掺量为50%的胶凝材料7 d水化放热量为171 J/g,较纯水泥的放热量降低了40.3%;在水胶比固定的情况下,粉煤灰的掺入可以降低混凝土的收缩率,粉煤灰掺量为30%时对混凝土的减缩效果最好。The cracking problem of concrete has always been an urgent problem to be solved in engineering.To improve the workability of concrete,reduce hydration heat release,and enhance its crack resistance,a comparative study was conducted on the various properties of concrete with different fly ash dosages,including mechanical properties,thermal properties,and long-term performance.The differences in various properties of concrete with different fly ash dosages were compared and analyzed.The results showed that with the increase of fly ash content,the strength of concrete showed a trend of decreasing in the early stage and rapidly increasing in the later stage.When the fly ash content reached 50%,compared with the specimens without fly ash,its 7-day compressive strength decreased by 40.3%,and the 60 day strength increased by 53.9%compared to the 7-day strength;The addition of fly ash significantly reduces the heat release rate of the cementitious system.The hydration heat release of the cementitious material with a 50%fly ash content after 7 days is 171 J/g,which is 40.3%lower than that of pure cement.;When the water cement ratio is fixed,the addition of fly ash can reduce the shrinkage rate of concrete,and the best shrinkage reduction effect is achieved when the fly ash content is 30%.

关 键 词：粉煤灰 抗裂混凝土 力学性能 水化热 干燥收缩 早期平板抗裂 

分 类 号：U454[建筑科学—桥梁与隧道工程]