基于疏水涂层改善混凝土防渗抗冻性的效果对比

Comparison of the Effect of Improving the Impermeability and Frost Resistance of Concrete Based on Hydrophobic Coating

在黑龙江省等高纬度寒冷地区,冬季降雪频繁,公路路面、桥面上的冰雪较多,出于交通安全和保通需要,降雪前后时常会在路面、桥面上撒布一定数量的除冰盐,容易导致路面、桥面的剥蚀损害,对桥梁混凝土钢筋的使用寿命也有较大影响。在混凝土表面进行疏水处理是改善混凝土防渗及抗冻性的有效措施之一。基于“氟化二氧化硅胶体”类疏水材料进行室内对比试验,确认采取常用涂布方式进行处理,可使混凝土的表面静态接触角达到145°以上,采取两遍喷涂或“先涂刷后喷涂”的方式效果最好。与未进行表面处理的试件相比,吸水率可降低68.3%;在冻融循环次数150次以内时,质量损失率可降低53.3%,100次以内时,抗弯拉强度损失率可降低79.5%。同时在抗盐冻,以及表面疏冰方面也有积极作用。

In high latitude cold regions such as Heilongjiang Province,winter snowfall is frequent,and there is more ice and snow on highway pavement and bridge deck.For the needs of traffic safety and traffic protection,a certain amount of deicing salt is often spread on the pavement and bridge deck before and after snowfall.It is easy to cause the erosion damage of pavement and bridge deck,and also has a great influence on the service life of bridge concrete reinforcement.Hydrophobic treatment on concrete surface is one of the effective measures to improve the impermeability and frost resistance of concrete.Based on the indoor comparative test of"fluorinated silica colloid"hydrophobic materials,it is confirmed that the surface static contact angle of concrete can reach more than 145°by using common coating methods,and the effect of two times spraying or"coating first and spraying later"is the best.Compared with the specimens without surface treatment,the water absorption rate can be reduced by 68.3%.When the number of freeze-thaw cycles is less than 150 times,the mass loss rate can be reduced by 53.3%,and the flexural strength loss rate can be reduced by 79.5%within 100 times.At the same time,it also plays an active role in salt freezing resistance and surface ice thinning.