轻骨料预湿程度对混合骨料混凝土力学性能的影响

研究了用不同预湿程度的页岩陶粒与碎石以体积比1：1混合配制的混合骨料混凝土拌合物性能和力学性能.结果表明,随着陶粒预湿时间的延长,混合骨料混凝土拌合物坍落度经时损失逐渐减小,7d抗压强度逐渐降低,劈拉强度与抗折强度在轻骨料预湿时间小于1h时略有增加.28d抗压强度、劈拉强度、抗折强度和弹性模量都逐渐增加.用预湿1h的陶粒配制的混合骨料混凝土7d与28d的拉压比和折压比与轻骨料混凝土相比几乎没有降低,其弹性模量比同条件的轻骨料混凝土高32.9%,比强度高10.5%.

Effect of prewetting degree of lightweight aggregate on mechanical properties of specified density concrete

The workability of fresh concrete and mechanical properties of hardened specified density concrete that incorporated pre-wetted shale ceramsite in different degrees and crushed stone in proportion of 1:1 by volume was studied. The results show that as prewetting time increases, the age loss of specified density concrete mixture decreases, and compressive strength at 7 days gradually reduces, but splitting tensile strength and flexural strength at 7 days has small increase when shale ceramsite prewetted 1hr, and the compressive strength, splitting tensile strength, flexural strength and elastic modulus at 28 days all gradually increase. The tension-compression ratio and flex-compression ratio of specified density concrete incorporated 1h prewetted shale ceramsite nearly have no reduction compared with lightweight concrete. The elastic modulus of specified density concrete is 32.9% higher than that of lightweight concrete, and specific strength is 10.5% higher than lightweight concrete.