石屑对混凝土工作性及强度的影响试验研究

针对石屑应用引起的细骨料性质波动,探究了石屑石粉含量、取代海砂比例对混凝土工作性、强度的影响,并提出了混凝土工作性调整的相关建议。结果表明,石粉含量每增加1%,外加剂适宜掺量需增加0.054%;当砂率小于41%时,石屑对混凝土工作性影响可不予考虑,当砂率大于41%时,应控制石屑比例不超过60%;当砂率为43%,石屑比例为40%时,中低强度等级混凝土的和易性、黏聚性达到最佳;混凝土外加剂与等效砂浆外加剂适宜掺量关系为:y=0.88x+0.39,可为细骨料波动下混凝土外加剂调整提供参考。

Experimental Research on the effect of Stone Chips on Workability and Strength of Concrete

Aiming at the fluctuation of fine aggregate properties caused by the application of stone chips,the influence of the content of stone powder and the proportion of replacing sea sand on the workability and strength of concrete was studied,some suggestions for the adjustment of workability were put forward.The results show that when the content of stone powder increases by 1%,the suitable amount of admixture needs to increase by 0.054%;when the sand ratio is less than 41%,the influence of stone chips has little effect on the workability of concrete;when the sand ratio is more than 41%,the proportion of stone chips should be controlled not to exceed 60%;when the sand ratio is 43%,the proportion of stone chips is 40%,the workability and cohesiveness of medium-low grade concrete are the best;the relationship of suitable amount of admixture between equivalent mortar and concrete is y=0.88x+0.39,which can provide reference for the adjustment of concrete admixture under the fluctuation of fine aggregate.