高性能混凝土配合比设计及力学强度试验研究

为提高混凝土的抗压强度和抗冲磨强度,通过不同配合比对普通混凝土进行试验分析。通过试验得出:石粉、灰土和钢渣对混凝土的抗压强度影响并不显著。随着石粉比例的增多,混凝土的抗压强度几乎无明显变化;随着灰土比例的增高,混凝土的抗压强度会出现降低趋势;而随着钢渣比例的增多,混凝土的抗压强度也会出现下降趋势,但影响较小;水灰比对混凝土的抗压强度的变化具有显著性,而砂率和用水量比例则对抗压强度的影响不大。当水灰比逐渐增大时,混凝土的抗压强度逐渐减小;砂率比例逐渐增大时,混凝土的抗压强度无明显变化;用水量比例增多时,混凝土的抗压强度会逐渐上升,但影响较小;石粉、灰土和钢渣对混凝土的抗冲磨强度影响并不显著。随着石粉比例的增加,混凝土抗冲磨强度增大,当石粉比例逐渐增加时,混凝土抗冲磨强度明显增大;随着灰土比例的增多,混凝土的抗冲磨强度减小,并且随着时间的增加,其强度减小趋势便更加明显;随着钢渣比例的增加,混凝土的抗冲磨强度下降,但影响不大。通过试验结果得出最佳混凝土配合比,并通过分析高性能混凝土与混凝土的微观特征得出:普通混凝土内部结构疏松并且有大量的孔洞、分布排列杂乱;而高性能混凝土内部结构较为密集,孔洞较少,高性能混凝土水化后,Ca和Si含量最多,而这两种元素能够形成稳定的结构,因此使得高性能混凝土抗压强度和抗冲磨强度提高。

Mix proportion design and mechanical strength test of high performance concrete

In order to improve the compressive strength and abrasive strength of concrete,experiments were carried out on ordinary concrete with different mix ratios.The experimental results show that the influence of lime powder,lime soil and steel slag on the compressive strength of concrete is not significant.With the increase of the proportion of stone powder,the compressive strength of concrete almost has no obvious change.With the increase of the proportion of lime-soil,the compressive strength of concrete will decrease.While with the increase of the proportion of steel slag,the compressive strength of concrete will also decrease,but the influence is small.The water-cement ratio has a significant change in the compressive strength of concrete,while the sand ratio and water consumption ratio have a significant change.However,it has little effect on compressive strength.When the water cement ratio increases gradually,the compressive strength of concrete decreases gradually.When the sand ratio increases gradually,the compressive strength of concrete has no obvious change.When the water consumption ratio increases,the compressive strength of concrete will gradually increase,but the influence is small.The impact of lime powder,lime soil and steel slag on the impact and abrasion strength of concrete is not significant.With the increase of the proportion of stone powder,the anti-abrasion strength of concrete increases,and when the proportion of stone powder increases gradually,the anti-abrasion strength of concrete increases obviously.With the increase of the proportion of lime-soil,the anti-abrasion strength of concrete decreases,and with the increase of time,the trend of its strength decreases more obviously.With the increase of the proportion of steel slag,the anti-abrasion strength of concrete decreases,but the influence is not obvious.The optimum mix ratio of concrete is obtained through the experimental results,and by comparing the micro-characteristics of high performance concrete and concrete,it is concluded that the internal structure of ordinary concrete is loose and there are a large number of holes and their distribution is disorderly.While the internal structure of high performance concrete is relatively dense,with fewer holes.After hydration of high performance concrete,the content of Ca and Si is the largest,and these two elements can form a stable state.As a result,the compressive strength and abrasive strength of HPC are improved.