摘要
在大体积补偿收缩混凝土内部 ,由于胶凝材料水化放热 ,其最高温度可能超过钙矾石的分解温度 ,使水化初期生成的钙矾石分解 ;并在温度降低以后 ,在硬化混凝土内重新生成。本文探讨了这种延迟钙矾石生成现象对混凝土性能的影响。发现延迟钙矾石生成在水化初期表面为补偿收缩混凝土的膨胀能损失 ,不能达到补偿温度收缩的目的 ;后期表现为混凝土的延迟膨胀。降低水胶比 ,掺加粉煤灰和矿渣等矿物掺和料有利于抑制DEF引起的后期膨胀。
? The temperature in the core of massive shrinkage compensating concrete is possibly higher than the decomposition temperature of ettringite due to the exothermic hydration of binder.Ettringite formed during the early hydrating period is decomposed,but reformed in the hardened concrete after the inner temperature falls.The effect of this delayed ettringite formation upon the properties of concrete is discussed.It was found that delayed ettringite formation results in the loss of expanding energy of massive shrinkage compenasting concrete in early hydrating age,which can not compensate the temperature shrinkage;and delayed expansion in later gae.It benefits to control the expansion introduced by DEF with decreasing W/B ratios and blending mineral admixture. 〔
出处
《混凝土》
CAS
CSCD
北大核心
2000年第6期18-21,共4页
Concrete
关键词
补偿收缩混凝土
延迟钙矾石生成
膨胀
shrinkage compensating concrete
delayed ettringite formation
expansion
