dc.description.abstract | In recent years, polymer has been used for modifying cementitious materials widely in order to improve its performance. However, the polymer-modified cementitious materials still have many shortcomings, such as low workability, poor durability and high costs. In order to improve the above-mentioned defects of the polymer-modified cementitious materials, studying and making a new kind of polymer is important.
Taking the expense and the construction condition into consideration and making the least influence on the research, we used different ethanol, ethylene glycol, diethylene glycol, lauryl alcohol and stearyl alcohol to carry on the etherification in this research. The Polyacrylic ester (PAE) was made under the consideration of the components, the dosage increase and the compatible situation. The polymer-modified cementitious materials were executed to evaluate the properties of flowability, mechanics, durability and pore structure with various PAE composition and dosages. The test results showed that the Polyacrylic ester (PAE) which was made from five species of ethylene glycol had the best effect, and that the optimum conditions of the reaction were determined according to the molar ratio of acrylic acid to ethylene glycol by 1: 0.2. As far as the workability was concerned, the flowability was increased by adding the amount of PAE. As to the hardened property, if PAE was dosed with 0.1% by weight of cement, the compressive strength of polymer-modified cementitious materials could improve up to 7%~12% of the OPC. The polymer-modified cementitious materials would make better water absorption, flexural strength and adhesion strength. Besides, the penetration of polymer modified concrete was lowered by adding RCPT. SEM micrographs showed that hardened Polymer formed the film layers in the cement-based composites. This sealed structure helped to improve the durability of the cementitious materials. But in this research, we only used typeⅠPortland cement to proceed experiments, so it still needed more information to evaluate the whole effects. | en_US |