泥灰岩石粉对自密实混凝土性能的影响

Effect of Limestone Powder on Properties of Self-compacting Concrete

通过石粉取代胶凝材料制备了一种低胶凝材料用量、低水泥用量的机制砂生态自密实混凝土,研究了石粉取代率对自密实混凝土工作性能、力学性能和抗氯离子渗透性能的影响。结果表明:掺入泥灰岩石粉可以明显提高机制砂自密实混凝土的工作性能;随着石粉取代率的提高,机制砂自密实混凝土的抗压强度略有下降,在满足该强度等级要求的同时解决了自密实混凝土强度富余的问题;泥灰岩石粉的掺入使机制砂自密实混凝土的抗氯离子渗透性能有所降低,但其仍具有较高的抗氯离子渗透性能。成功配置了C35强度等级的机制砂生态自密实混凝土,胶凝材料用量为354kg/^(m3,水)泥用量为195kg/m^(3);坍落度255mm,坍落扩展度640mm,T500测试时间3.8s,V形漏斗测试时间31s,间隙通过性5mm;符合SF1,VS1,PA2,SR2性能等级的自密实混凝土。

A new type of manufactured sand ecological self-compacting concrete(ECO-SCC)with less cement and less cementitious materials was prepared by replacing the cementitious materials with limestone powder.The effect of limestone powder replacement ratio on the workability,mechanical properties and resistance to chloride ion permeability of self-compacting concrete was studied.The experimental results show that the incorporation of limestone powder can significantly improve the workability of manufactured sand self-compacting concrete.With the increase of limestone powder replacement ratio,the compressive strength of manufactured sand self-compacting concrete decreases,but it still meets the requirements of the strength grade,and solves the problem of strength surplus of self-compacting concrete.The incorporation of limestone powder reduces the resistance to chloride ion permeability of manufactured sand self-compacting concrete,but it still has high resistance to chloride ion permeability.C35 strength grade manufactured sand ecological self-compacting concrete was successfully configured,utilization amount of cementitious materials dosage is 354 kg/m^(3),cement dosage 195 kg/m^(3),slump to 255 mm,slump flow to 640 mm,T500 test time for3.8 s,V-shaped funnel test time 31 s,and clearance 5 mm,which is in line with SF1,VS1,PA2,and SR2 performance levels of self-compacting concrete.