通过对红砂岩进行崩解试验，总结了其崩解规律及崩解机理；分别利用水泥及石灰对崩解土进行改良处理，对养护28 d龄期后的红砂岩改良土进行干湿循环和长期浸水试验，探究其在干湿循环和长期浸水条件下无侧限抗压强度及质量的变化规律。研究结果表明，红砂岩水稳定性极差，遇水后极易崩解，第一次崩解后，粒径大于5 mm的颗粒含量仅剩31%，粒径越大，崩解性就越强，崩解速度就越快；利用水泥和石灰改良后的红砂岩，水稳定性大大提高。胶凝材料掺量较高(8%)时，经5次干湿循环后，水泥改良土的强度损失率低于石灰改良土，试件结构较为完整，质量损失率与石灰改良土基本相同。故高掺量时，水泥改良土抗干湿循环的能力更强；胶凝材料掺量较低(4%、6%)时，水泥改良土的强度损失率高于石灰改良土，试件破损严重，有大块脱落现象，质量损失率高于石灰改良土。故低掺量时，石灰改良土抗干湿循环的能力更强。长期浸水条件下，改良土的干缩湿胀作用较小，且胶凝材料继续发生水化反应，故水泥改良土和石灰改良土强度均呈现上升趋势。相比而言，水泥改良土强度增长幅度更高，长期浸水下表现的水稳定性更好。
Through the disintegration test of red sandstone, the disintegration law and disintegration mech-anism are summarized. The dry-wet cycle and long-term water immersion test of red sandstone improved soil were carried out to study the variation law of unconfined compressive strength and quality of red sandstone improved soil under dry and wet cycles and long-term water immersion conditions. The results show that the red sandstone has very poor water stability and is easily disintegrated after water contact. After the first disintegration, the content of particles larger than 5 mm is only 31%. And the larger the particle size, the stronger the disintegration and the faster the disintegration speed. The cement and lime are used to solidify the disintegrated soil separately. When the amount of cementing material is higher (8%), after 5 dry and wet cycles, the strength loss rate of cement-modified soil is lower than that of lime-modified soil. The structure of the test piece is relatively complete, and the mass loss rate is basically the same as that of lime-modified soil. Therefore, when the amount of the mixture is high, the water stability of the cement-modified soil is better than that of the lime-modified soil. When the amount of cementing material is low (4%, 6%), the strength loss rate of cement-modified soil is higher than that of lime-modified soil. The specimen was severely damaged, and the mass loss rate was higher than that of lime-modified soil. Therefore, the lime-modified soil has good water stability when the amount is low. Under long-term water immersion conditions, the dry shrinkage and swelling effect of the improved soil is small, and the cementitious material continues to undergo hydration reaction. Therefore, the strength of cement improved soil and lime improved soil has an upward trend. In comparison, the strength of cement-modified soil increases more, and the water stability of long-term immersion is better.
