再生粗骨料取代率对碎卵石混凝土抗压性能影响研究

设计制作了再生粗骨料取代率r=0%、30%、50%、70%、100%的碎卵石混凝土立方体及棱柱体试件，在不同龄期下对其进行抗压试验。研究了五种再生粗骨料取代率下，不同龄期的混凝土立方体抗压强度以及棱柱体抗压强度的变化趋势。结果表明：在龄期为3 d和7 d情况下，r=30%时混凝土的抗压强度较r=0%时无显著变化；当r>30%时，混凝土的抗压强度随r的增加呈下降趋势，且下降幅度较明显。在龄期为14 d和28 d情况下，各组试件的抗压强度随着r的增加而降低。提出了考虑再生粗骨料取代率r的情况下，混凝土立方体抗压强度与棱柱体抗压强度相关关系计算模型f_c=（-0.190 3r²+0.148r+0.722 7）f_cu。

Experimental Study on Compressive Performance of Crushed Pebble Concrete Containing Reclaimed Aggregate

The cube and prism specimens of gravel concrete with replacement ratio of recycled coarse aggregate r=0%, 30%, 50%, 70% and 100% were designed and manufactured. The change trend of cube compressive strength and prismatic compressive strength of concrete at different ages under different replacement rates of recycled coarse aggregate was studied. The results show that the compressive strength of concrete has no significant change when r is 30% when the age is 3 d and 7 d; If r is more than 30%, the compressive strength of concrete tends to decrease when r increases, and the decrease range is obvious. At the age of 14 d and 28 d, the compressive strength decreased with the increase of r. A calculation model for the correlation between cube compressive strength and prismatic compressive strength is proposed when the replacement ratio of recycled coarse aggregate is considered. The model is f_c=(-0.190 3r²+0.148r+0.722 7)f_cu.