不饱和聚酯树脂混凝土性能优化及抗冻性

Performance Optimization and Frost Resistance of the Unsaturated Polyester Resin Concrete

不饱和聚酯树脂混凝土(UPC)较普通混凝土具有强度高、耐腐蚀等优点,适用于复杂服役环境,其力学性能及耐久性研究较少。本文旨在探究粉煤灰掺量对UPC力学性能的影响及UPC的抗冻性能。本文共设置五种粉煤灰掺量(0%、5%、10%、15%及20%),分别进行了不同粉煤灰掺量下UPC的抗压强度试验、抗折强度试验及劈裂抗拉强度试验。试验结果表明粉煤灰掺量为10%时,UPC抗压强度、抗折强度和劈裂抗拉强度均达到最大值,因此确定粉煤灰掺量为10%是最优掺量。利用SEM对比分析了未掺粉煤灰和煤灰掺量为10%时UPC的微观结构。对粉煤灰掺量为10%的UPC进行了50次、100次、150次、200次和250次的冻融循环试验,结果表明随冻融循环次数的增加,UPC质量损失逐渐增大,力学性能降低。UPC质量损失总体较小,250次的冻融循环后质量仅损失0.37%。力学性能以劈裂抗拉强度下降最为明显达到28.44%,高于抗压强度(9.77%)和抗折强度(11.71%)的损失率。

Compared with ordinary concrete,unsaturated polyester resin concrete(UPC)has the advantages of high strength,corrosion resistance and adaptability to complex service environment.However,there are only a few studies related to its mechanical properties and durability performance.This paper aims to explore the influence of fly ash content on the mechanical property and frost resistant performance.In this paper,fly ash content was set to 0%,5%,10%,15%and 20%and compressive strength,flexural strength and splitting tensile strength were tested.According to the results,UPC with fly ash content of 10%showed the highest compressive strength,flexural strength and splitting tensile strength.Therefore,it is determined that 10%of fly ash is the optimal dosage for preparing UPC.SEM was applied to compare and analyze the microstructure of UPC without fly ash and fly ash content of 10%.The results of freeze-thaw test of 50,100,150,200 and 250 cycles carried out on UPC with 10%fly ash content show that the mass loss of UPC gradually increased with the increase of freeze-thaw cycles,leading to decreased mechanical properties.The overall mass loss of UPC was small,and the mass loss was only 0.37%after 250 freeze-thaw cycles.For the mechanical strength,the splitting tensile strength decreased most obviously,reaching 28.44%,which was higher than the loss rate of compressive strength(9.77%)and flexural strength(11.71%).