模网混凝土聚合物改性砂浆保护层性能研究

【作者】 史巍；

【导师】 王立久； 任铮钺；

【作者基本信息】 大连理工大学 ， 材料学， 2002， 硕士

【摘要】 本文主要对模网混凝土聚合物改性水泥砂浆保护层的性能进行研究，着重探讨了与耐久性密切相关的抗裂性能和抗渗性能。利用材料复合的原理在普通砂浆中掺入丁苯胶乳形成聚合物改性水泥砂浆代替传统的普通水泥砂浆作为模网混凝土的表面保护层，以改善面层砂浆的抗裂性、抗渗性、柔韧性，提高其与模网混凝土的协调变形能力，从而保护内部钢模网不受锈蚀并最终提高模网混凝土的耐久性。 在改善砂浆抗裂性、提高柔韧性和协调变形能力方面，进行了不同聚合物掺量的强度试验、弹性模量试验；设计了与模网混凝土实际结构和情况相接近的新老砂浆粘结强度试验、砂浆与苯板的粘结试验以及混凝土环中的砂浆收缩试验；进行了不同强度、不同聚合物掺量下的砂浆干缩变形试验、温度变形试验，以及不同结构形式的钢网自身温度变形试验和配有钢网的砂浆温度变形试验。 在改进砂浆的密实度和抗渗性能方面，主要进行了不同聚合物掺量下的吸水性试验、可透孔隙率试验、耐老化性试验、抗冻性试验、抗碳化试验，以及对耐久性能影响最大的快速氯离子扩散试验，并和普通砂浆的相应试验进行了对比分析，验证了聚合物砂浆的改性效果。 在上述试验基础上，从微观角度对改性前后的水泥砂浆进行扫描电镜分析，结合砂浆微观结构，深入分析聚合物改性水泥砂浆的改性机理。经过试验研究和微观理论分析后，得出改性砂浆中聚合物的最佳掺量为9％的结论。最后考虑经济因素，对改性砂浆的拌和工艺和工程造价进行了探讨，使其在聚合物掺量较低的情况下获得优良的性能，对推广其工程应用具有很大的经济意义。更多还原

【Abstract】 In this paper the properties of the polymer modified cement mortar are studied of DIDY formwork concrete surface coated layer for protection. The emphasis is focused on the permeability and cracking-proof feature. Use the principle of material complex, carboxylic styrene-butadiene rubber latex added to the ordinary mortar forms PMM which takes the place of the conventional mortar as the surface coated. It can improve the cracking-proof feature, permeability, flexibility, as well as the compatibility with formwork concrete, to protect the formwork from corrosion and finally to enhance the durability of formwork concrete.In the aspect of improving the cracking feature, compatibility and flexibility, the author has done experiments, including strength, modulus of elasticity experiments, and design some experiments similar to the practical structure and circumstance including adhesion strength between fresh mortars and old ones, between mortar and polystyrene board, mortar shrinkage in concrete circle, mortar shrinkage at different strength and different polymer-cement ratio, and temperature deformability at different strength and different polymer-cement ratio on mortars, on different type of formwork and on mortars with different type of formwork.In the aspect of mortar permeability the author has done some experiments, including the water absorption, porosity, weatherability, anti-freeze-thaw cycle, carbonation and the chloride diffusion experiment, and compared those properties with conventional mortar to testify the modified effects.On the base of these experiments, the method of SEM was used to analyze the microstructure and hydration mechanism of polymer modified cement mortar, and the author draws a conclusion that the 9 percent of polymer-cement ratio is the optimum ratio. Finally, make allowance for economic factors, the mixture technique and engineering cost are discussed. The PMM can be gained better properties at a low polymer-cement ratio, which have a great economic significance to enlarge its engineering application.更多还原