WHDF增强密实(抗裂)剂对改进面板砼抗裂性能的影响

WHDF增强密实(抗裂)剂,是一种应用于面板堆石坝面板混凝土抗裂的高性能外加剂。笔者运用化学热力学和动力学等研究方法,从砼的微观结构着手,研究水泥水化机理,把水泥水化程度和水化产物与外加剂的抗裂作用机理结合起来研究,使得WHDF抗裂剂能促进水泥水化程度,优化水化产物和协同激发砼中活性混合材料与Ca(OH)2进行二次水化,从而提高砼中凝胶量,降低孔隙率,改善水泥石及其与骨料界面的结构,增强凝胶的粘结力,使砼具有良好的抗裂性能。湖北小溪口电站等近十个水电工程的面板混凝土掺用WHDF后,混凝土表面平滑光泽,均无收缩裂缝产生。

The influence of WHDF crack resistance agent on improving crack resistance characteristics of concrete face-slab

WHDF reinforcement dense(cracking resistance) agent is a high performance additive for cracking resistance in face slab for CFED.The hydration mechanism of the concrete through microstructure by using thermodynamics and kinetics method is studied in this paper.The combination of hydration extent of hydration product with cracking resistant mechanism of the additive is studied so that WHDF promote concrete hydration extent,optimize hydration product and stimulate secondary hydration reaction between active component of concrete and Ca(OH)-2 so as to increase amount of gel,decrease porosity,improve surface structure of concrete and aggregate,increase adhesive force of gel and then insure good cracking resistance characteristics of concrete.The concrete structures of about 10 small hydropower station including Xiaoxikou have smooth surface without shrinking crack affter using this additive.