某高速公路红层泥岩路基填料改良试验研究
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摘要
分别选用石灰、粉煤灰、水泥作为改良剂,对某高速公路红层泥岩填料进行改良。对改良后的15组试样进行最优含水率、CBR值、无侧限抗压强度、耐崩解性、水稳定性的测试,并作电子显微镜扫描。结果表明:粉煤灰对最优含水率影响较大,石灰次之;水泥、石灰、粉煤灰对无侧限抗压强度、耐崩解性的改善整体排序为水泥>石灰>粉煤灰;相同配比情况下,水泥对填料的整体改善作用最好,石灰次之,当石灰掺入比为7%时无侧限抗压强度最大,即为最优配比。
For red mudstone cannot be used as the subgrade filler directly,the red mudstone filler on an expressway was improved by using lime,fly ash and cement as a modifier respectively. The optimum moisture content,CBR value,unconfined compressive strength,resistance to disintegration and water stability test as well as electron microscope scanning were carried out on the 15 modified samples. The results show that the effect of fly ash on the optimal water content is larger than that of lime. The sequence of improvement effect on unconfined compressive strength and resistance to disintegration among cement,lime and fly ash is cement >lime > fly ash. Under the same modifier ratio,the cement is the strongest,lime is inferior and the fly ash is the worst on the overall effect. When the lime ratio is 7 %,the unconfined compressive strength is the largest,i. e.,the best ratio. The modification of micro structure shows that the modified agent is achieved the purpose of improving the stability of subgrade filler by hydration reaction with the combined water and free water through ion exchange with the clay minerals in the red mudstone.
For red mudstone cannot be used as the subgrade filler directly,the red mudstone filler on an expressway was improved by using lime,fly ash and cement as a modifier respectively. The optimum moisture content,CBR value,unconfined compressive strength,resistance to disintegration and water stability test as well as electron microscope scanning were carried out on the 15 modified samples. The results show that the effect of fly ash on the optimal water content is larger than that of lime. The sequence of improvement effect on unconfined compressive strength and resistance to disintegration among cement,lime and fly ash is cement >lime > fly ash. Under the same modifier ratio,the cement is the strongest,lime is inferior and the fly ash is the worst on the overall effect. When the lime ratio is 7 %,the unconfined compressive strength is the largest,i. e.,the best ratio. The modification of micro structure shows that the modified agent is achieved the purpose of improving the stability of subgrade filler by hydration reaction with the combined water and free water through ion exchange with the clay minerals in the red mudstone.
引文
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[8]陈花林.石灰改良泥质粉砂岩路基填料的试验研究[J].铁道工程学报,2008(3):10-14.CHEN H L.Experimental research on the improving filling materials with lime for argillaceous sandstone subgrade[J].Journal of Railway Engineering Society,2008(3):10-14.
[9]汪海洋,李粮纲,余雷.水泥和石灰改良路基填料对比试验研究[J].水利水运工程学报,2010(2):114-118.WANG H Y,LI L G,YU L.Expermental studies on improving subgrade soil with cement and lime[J].Hydro-Science and Engineering,2010(2):114-118.
[10]陈湘亮,王永和,王灿辉.泥质粉砂岩改良土路基填料适宜性试验分析[J].中南大学学报(自然科学版),2013,44(10):4287-4293.CHEN X L,WANG Y H,WANG C H.Experimental study of suitability of argillaceous siltstone improved soil as filling for subgrade[J].Journal of Central South University(Science and Technology),2013,44(10):4287-4293.
[2]刘晓明.红层软岩崩解性及其路基动力变形特性研究[D].长沙:湖南大学,2006:4.LIU X M.Research on slaking properties of red beds soft rock and dynamic deformation properties of embankment[D].Changsha:Hunan University,2006:4.
[3]卿三惠,黄润秋,曹新文.红层软岩填筑路堤的离心模型试验[J].铁道工程学报,2007(2):41-46.QING S H,HUANG R Q,CAO X W.Centrifugal model test of red and soft rock-filled embankment[J].Journal of Railway Engineering Society,2007(2):41-46.
[4]吴胜军,刘龙武,王桂尧.红粘土路基裂缝开展规律室内试验研究[J].中外公路,2011,31(1):22-25.
[5]张中云,蒋关鲁.客运专线无碴轨道红层泥岩改良土路基离心模型试验研究[J].铁道科学与工程学报,2010,7(5):41-46.ZHANG Z Y,JIANG G L.Research on centrifugal model test of improved red mudstone embankment for unallasted truck[J].Journal of Railway Science and Engineering,2010,7(5):41-46.
[6]孔祥辉,蒋关鲁.循环荷载下红层泥岩路基土的变形特性研究[J].铁道标准设计,2013(2):1-4.KONG X H,JIANG G L.Study on deformation property of red bed mudstone of subgrade under cyclic loads[J].Railway Standard Design,2013(2):1-4.
[7]谢明宇,郑甲佳,吴立坚.贵州黔东南红粘土路基填筑技术研究[J].公路交通科技,2013(7):91-93,117.
[8]陈花林.石灰改良泥质粉砂岩路基填料的试验研究[J].铁道工程学报,2008(3):10-14.CHEN H L.Experimental research on the improving filling materials with lime for argillaceous sandstone subgrade[J].Journal of Railway Engineering Society,2008(3):10-14.
[9]汪海洋,李粮纲,余雷.水泥和石灰改良路基填料对比试验研究[J].水利水运工程学报,2010(2):114-118.WANG H Y,LI L G,YU L.Expermental studies on improving subgrade soil with cement and lime[J].Hydro-Science and Engineering,2010(2):114-118.
[10]陈湘亮,王永和,王灿辉.泥质粉砂岩改良土路基填料适宜性试验分析[J].中南大学学报(自然科学版),2013,44(10):4287-4293.CHEN X L,WANG Y H,WANG C H.Experimental study of suitability of argillaceous siltstone improved soil as filling for subgrade[J].Journal of Central South University(Science and Technology),2013,44(10):4287-4293.