基于碎石最大堆积密度的C30泵送混凝土胶凝材料用量优化研究

Study on the Optimization of Cementitious Material Dosage of C30 Pumped Concrete Based on the Maximum Stacking Density of Crushed Stone

预拌混凝土生产中多采用连续级配的碎石,然而由于碎石颗粒级配大多不够合理,为保证混凝土性能,往往需要提高胶凝材料用量,这样会导致混凝土生产成本提高,开裂敏感性增加。基于此,本文以实际生产C30泵送混凝土为对照组,通过对实际生产中所用碎石进行分级复配,对最大堆积密度条件下制备的混凝土胶凝材料的用量进行了优化研究。结果表明,在相同的C30泵送混凝土拌合物、力学性能和干燥收缩要求下,碎石中5~10mm和10~25mm粒径石子按质量比20∶80分级复配,相比于实际生产用碎石制备的混凝土能够显著降低胶凝材料的用量20kg/m~3,为实际生产中优化C30泵送混凝土性能及降本增效提供了参考。

Continuous graded crushed stone is often used in the production of ready mixed concrete.However,due to the unreasonable particle grading of crushed stone,in order to ensure the performance of concrete,it is often necessary to increase the amount of cementitious material,which will increase the production cost of concrete and increase the cracking sensitivity.Based on this,this paper takes the actual production of C30 pumped concrete as the control group,and optimizes the dosage of concrete cementitious materials prepared under the condition of maximum bulk density by grading and compounding the crushed stones used in the actual production.The research results show that under the same requirements of C30 pumped concrete mixture,mechanical properties and drying shrinkage,the graded combination of 5~10mm and 10~25mm stones in the gravel according to the mass ratio of 20∶80 can significantly reduce the amount of cementitious material by 20~30kg/m~3 compared with the concrete prepared from the actual production gravel,which provides a reference for optimizing the performance of C30 pumped concrete,reducing cost and increasing efficiency in the actual production.