再生粗骨料含量对混凝土力学性能的影响

Recycled Coarse Aggregate Content on the Mechanical Properties of Concrete Physical Regeneration

本实验目的是研究再生粗骨料取代原来混凝土中石子的含量后对混凝土力学性能的影响,再生粗骨料的来源为废弃混凝土。将其按要求压碎后以0-100%的取代率（中间级差为10%）取代原混凝土中的石子含量,得到11种再生混凝土。在每种取代率的混凝土下制作3个标准混凝土立方体试块（150 mm×150 mm×150 mm）,3个标准混凝土棱柱体试块（150 mm×150 mm×300 mm）,3个尺寸为150 mm×150 mm×550 mm试件共得到33个标准混凝土立方体试块,33个标准混凝土棱柱体试块,33个150 mm×150 mm×550 mm试件。然后按照标准试验方法进行力学性能试验。通过实验测得不同再生粗骨料取代率下再生混凝土的立方体抗压强度、轴心抗压强度、抗折强度、应力应变变化曲线、弹性模量等力学性能指标之间的关系。实验结果表明：当粗骨料取代率不断增加后,再生混凝土立方体抗压强度与轴心抗压强度呈现不断上升趋势,抗折强度呈现先上升后降低趋势,而弹性模量总体呈现下降趋势。综合考虑再生混凝土基本力学性能指标和经济性能指标,建议以30%~40%作为再生混凝土的最优取代率。

The purpose of this experiment is to study the effect on the mechanical properties of concrete recycled coarse aggregate after replace the content of the original concrete stones,recycled coarse aggregate source for the waste concrete. After pressing its claim crushed 0 - 100% substitution rate（ intermediate differential of 10%） to replace the original concrete gravel content,get 11 kinds of recycled concrete. Country of three standard concrete test cubes（ 150 mm × 150 mm × 150 mm） in each concrete substitution rate, three standard concrete prism test piece（ 150 mm × 150 mm × 300 mm）,3 a size of 150 mm ×150 mm × 550 mm test members received a total of 33 standard concrete test cubes,33 standard concrete prism test block,33150 mm × 150 mm × 550 mm specimen. Then follow standard test method of mechanical properties test. Experimentally measured by different regeneration recycled coarse aggregate replacement rate under concrete cube compressive strength,axial compressive strength,flexural strength,stress- strain relationship curves, elastic modulus and other mechanical properties between. The results showed that： When replace coarse aggregate rate increased,recycled concrete cube compressive strength and showing a rising trend axial compressive strength, flexural strength after first showing an upward trend lower,while the elastic modulus of the overall downward trend. Considering the regeneration of basic mechanical properties of concrete indicators and economic performance indicators, the proposed 30%-40% as the optimal replacement ratio of recycled concrete.