Study On The Anti-UV Performance Of W-OH Consolidating Pisha Sandstone

Pisha area was one of the main sources of the sand in Yellow River. Therefore, it was important for the sediment control of Yellow River to manage the water and soil loss in the pisha area. W-OH as a novel consolidation material could be used to control Pisha sandstone. As a kind of polyurethane. W-OH would be photodegraded under UV. which had effect on the performance of W-OH in the actual applied projects. Taking the novel material W-OH for research object, this paper analyzed the anti-UV performance and consolidation performance of W-OH by studying the mass loss and mechanical property change of W-OH and the pisha sandstone consolidated by W-OH. The effect of different factors (irradiation time, concentration, spray amount, the type and concentration of additives and so on) was studied. The main results as follow:1. The results on the anti-UV performance of W-OH showed that at the beginning of the irradiation, the mass of W-OH decreased obviously and the tensile strength increased in a certain extent. Then the re-polymerization disappeared. The loss of mass was not obvious and the tensile strength decreased constantly. In the neutral environment, the anti-UV performance and tensile strength of W-OH had the best effect. Compared with alkaline environment, acid environment had worse effect. PVA and EVA could improve the anti-UV performance of W-OH by enhancing the consolidation of W-OH obviously. The anti-UV performance of W-OH increased with the increase of concentration. UV531 and UV770 could improve the anti-UV performance of W-OH obviously. The anti-UV performance of W-OH increased with the concentration increasing. When the concentration of UV531 or UV770 was higher than 0.06%. the anti-UV performance of W-OH was good enough. The mixture of two ultraviolet agents with 1:1 had better effect than just adding one.2. The results on the anti-UV performance of the Pisha sandstone consolidated by W-OH showed that the compressive strength of samples surface layer increased at the beginning of UV irradiation. With the irradiation time increasing, the compressive strength decreased. The concentration could improve the anti-UV performance and mechanical strength of the samples. The mechanical strength and anti-UV performance of the pisha sandstone had the best effect in the neutral environment. The property of the pisha sandstone decreased in the acidic and alkaline environment. PVA and EVA increased the anti-UV performance of the pisha sandstone by enhancing mechanical property obviously. The anti-UV performance increased with the increase of PVA and EVA concentration. UV531 and UV770 could increase the anti-UV performance of pisha sandstone. The anti-UV performance increased with the concentration of UV531 and UV770 increasing. When the concentration of UV531 or UV770 was higher than 0.06%, the samples had good anti-UV performance. The anti-UV performance had the best effect when the addition proportion of UV531 and UV770 was 1:1.3. The lifetime of the consolidation layer increased with the increase of W-OH and additives concentration. The lifetime of the consolidation layer was different in the different additives (UV770>UV531>PVA>EVA). When the concentration of PVA and EVA was lower than 2.5%, the effect of PVA on the consolidation layer was better than that of EVA. When the concentration of PVA and EVA was higher than 2.5%, the effect of PVA was similar to that of EVA. At the same concentration, the effect of UV770 was a little better than that of UV531.