粗骨料对自密实混凝土性能影响的试验研究

Influence of aggregate on properties of Self-Compact Concrete

主要研究了粗骨料体积含量、类型以及最大粒径对自密实混凝土工作性、强度、弹性模量以及收缩等性能的影响。结果表明:粗骨料与砂浆体积比(V_g/V_m)显著影响自密实混凝土拌和物的流动性、间距通过性以及稳定性(抗离析性),存在最佳的V_g/V_m使得混凝土拌和物获得自密实性。减小粗骨料的最大粒径,新拌自密实混凝土的稳定性提高。保持浆体体积不变,自密实混凝土的劈拉强度随V_g/V_m增加而显著降低。

This paper investigates the influences of volume content,type and maximum size of coarse aggregate on properties of self-consolidating concrete(SCC)such as workability,strength,elastic modulus and drying shrinkage.Results indicates the flowability,passing capability and stability of fresh SCC are greatly influenced by ratio of volume between coarse aggregate and mortar(V_g/V_m).There exists an optimum value of V_g/V_m to achieve best workability of SCC.Compared with crushed stone, gravel is more effective in improving flowability,passing capability and stability of fresh SCC.The decrease of maximum size of coarse aggregate also benefits to stability of fresh SCC.Under the same total aggregate volume condition,split strength of SCC reduce remarkably with increasing of V_g N_m.However,its corresponding compressive strength and elastic modulus only decreases slightly.Furthermore,the drying shrinkage of SCC will be reduced by increasing V_g/V_m or increasing maximum diameter of coarse aggregate.