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The Studies Of Cement Asphalt Mortar Modified With Waste Rubber Powder

Posted on:2013-01-01Degree:MasterType:Thesis
Country:ChinaCandidate:B B ZhangFull Text:PDF
GTID:2232330362474146Subject:Chemistry
Abstract/Summary:PDF Full Text Request
CA mortar is one of the key technologies of slab ballastless track, which issandwiched between two slabs and serves the purpose of supporting and adjusting ofslab track, absorbing the load of high-speed train, isolating from vibration damage. CAmortar is composed of cement, fine aggregate, asphalt emulsion, water and a variety ofadditives and is a high performance organic-inorganic composite material which has thecombined merits of high strength of cement and good elasticity of asphalt.CA mortar is modified by waste rubber power which takes the place of emulsifiedasphalt to reduce the mortar cost, and the performance is studied in this paper. Theresults have indicated that:(1) the root cause of influencing the performance of CAmortar is the rubber powder that is rough surface, lipophilic and insensitive to thetime-temperature effect.(2) The early strength of CA mortar would be affected byfeeding order, and the two kinds of order have their own characteristics.(3) With theincrease of the rubber power content, the work performance of CA mortar has becomepoor; gas content, expansion ratio increased, but resolution would be decrease.(4) Themechanical properties of CA mortar also have been influenced by rubber powder. Theinitial compressive strength of CA mortar has decreased with the increasing of wastedrubber powder content, but the strength increased after28days.(5) Cement-Asphaltratio is one of the main influence factors on the compressive strength of CA mortar. Thecompressive strength is proportional to the ratio.(6) The compressive strength of CAmortar has decreased with the rising of temperature and increased with the increasing ofloading speed, and the elastic modulus has decreased with the rising of temperatureregardless of the content of rubber power.(7) The content of rubber power has beenhigher, the sensitiveness of CA mortar to temperature has been lower and the influenceof loading rate on the compressive strength of CA mortar has been more unobvious.These mean the stability of CA mortar with rubber power has been better and thetime-temperature effect of CA mortar can be improved by rubber powder.The micrographs of CA mortar show that the distribution of inorganic phase andorganic phase in CA mortar can be improved by the rubber powder, thereby thehomogeneity of CA mortar is increased, and the content of free asphalt in CA mortar isreduced. Consequently, the time-temperature effect of CA mortar can be improved byrubber powder. Cost analysis shows that every5%of emulsified asphalt is replaced by the rubber powder,2.6%of the cost of CA mortar will be saved. This indicates that CAmortar is modified with the waste rubber powder is economically feasible. Theseprovide a basis for future research in this field.
Keywords/Search Tags:CA mortar, waste rubber power, time-temperature effect, mechanicalproperties, slab ballastless track
PDF Full Text Request
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