骨料粒径对珊瑚混凝土力学性能影响

Effects of Coral Aggregate Particle Size on Mechanical Properties of Coral Concrete

为研究珊瑚粗骨料粒径对珊瑚混凝土力学性能的影响,开展0.50,0.40和0.33共3种水灰比(w/c)条件下,5~10,5~20 mm和5~31.5 mm连续级配的珊瑚混凝土力学性能试验研究。研究结果表明:新拌全珊瑚混凝土流动性受骨料粒径影响显著,受条状、树枝状骨料占比的增加影响,骨料粒径越大流动性越差,主要原因是,其咬合互锁作用不利于骨料的翻转,降低了新拌珊瑚混凝土流动性;粒径大小对于珊瑚混凝土破坏过程存在一定影响,主要表现为破坏面处骨料贯穿破坏数量,但最终破坏形态差距并不明显;较大粒径珊瑚骨料有利于增强低水灰比条件下珊瑚混凝土抗折强度,不规则排列的珊瑚碎屑条状特性颗粒在水泥砂浆强度较低时表现出一定的桥接能力,随着水泥砂浆强度提高,其增强效果逐渐降低。

In order to study the effect of the size of coral coarse aggregate on the mechanical properties of coral concrete,this paper carried out continuous grading of coral concrete with 5-10,5-20 mm and 5-31.5 mm under three water-cement ratio conditions of 0.50,0.40 and 0.33.The research results show that the fluidity of newly mixed coral concrete is significantly affected by the aggregate particle size,and the larger the aggregate particle size is,the worse the fluidity will be.The main reason is that its bite-and-lock action is not conducive to the flipping of the aggregate,which reduces the liquidity of the fresh coral concrete.Moreover,particle size has a certain influence on the destruction process of coral concrete,which is mainly reflected in the amount of aggregate penetrating the failure at the failure surface,but the difference in the final failure form is not obvious.Large-size coral aggregate is conducive to enhancing the resistance strength of coral concrete under the condition of low water cement ratio.The irregular arrangement of coral-debris strip characteristic particles shows a certain bridging ability when the strength of cement mortar is low,and the enhancement effect gradually decreases with the increase of the cement motar strength.