轻质聚合物水泥砂浆的弯曲疲劳特性研究

A Study on Flexural Fatigue Property of Light Polymer Modified Cement Mortar

基于轻质混凝土与聚合物改性水泥混凝土的优越性,开展合理选材与配合比设计研究,研制同时具备这两种混凝土优点的水泥砂浆,并对所研制的轻质聚合物水泥砂浆进行抗压强度、抗折强度、疲劳性能、应力应变曲线特点和改性机理等进行了分析。研究发现:所研制的砂浆密度约1800 kg/m3,为轻质砂浆;丙烯酸乳液的掺入有利于降低轻质砂浆水灰比、改善浆体工作性、增大轻质砂浆的柔韧性与抗裂性,但存在一个最佳掺量问题;通过机理分析,发现具有高抗拉强度的聚合物膜是显著改善其抗折强度、压折比、弯曲韧性和疲劳性能等一系列力学性能的根本原因。结果表明:轻质聚合物砂浆是一种性能优异的柔韧性水泥基材料,建议可在对厚度、自重和柔韧性有一定要求的桥面铺装层等地方使用。

Based on the advantage and great achievements of light concrete and polymer modified cement mortar in civil engineering, reasonable materials are selected and designed to prepare cement mortar, with both advantages. And flexural strength, compressive strength, fatigue, characteristics of stressstrain curves and modified mechanism of light polymer modified cement mortar are analyzed. The results show that the density of mortar is about 1 800 kg/m^3 , light mortar. Acrylic acid can decrease water-cement ratio, improve paste working property, increase flexibility and crack resistance of the mortar, and there is a best dosage. Action mechanism shows that high-tensile strength of the polymer membrane is sig- nificant to improve mechanical properties of light polymer modified cement mortar. It means that light polymer mortar is an excellent flexible cement material. And it can be used at some place where thickness, weight and flexibility are specially required, such as bridge deck pavement, etc.