Research On The Static Stabiliyt Of The Filling Layer Scc Of CRTSⅢ Type System

As the filling material of the specific filling layer of the CRTSⅢ type system, the stability of SCC has big influences on the normal use of the track system, so a stable SCC has a significant meaning for the benefit of the society and economy, and which can also benefit the development of the high speed railway.Based on the static stability of filling layer SCC of CRTSⅢ slab ballastless track system, a simple introduction of the static segregation mechanism of SCC was made, the raw materials and the experimental method were confirmed, and the penetration test, the column test and the sieve segregation test were selected as the reference test method. And based on the test, the column test was improved, the effect of the parameters of the mix design and the workability and the vertical deformation of SCC on the static stability were studyed, meanwhile, a connection was also made between the workability and the static stability of SCC.Through the research, it was found that, increasing the W/B, dosage of SP and diameter of the coarse aggregate could improve the basic workability but decrease the static stability of SCC, but the expansion agent and the coarse aggregate volume fraction have the opposite effect. the grading curve of coarse aggregate is optimal, the workability and static stability of SCC will changed symmetric around it. Based on the difference of the coefficient of variation, the parameters which have influence to the static stability of SCC could ranking as W/B>Volume frication of aggregate>Dosage of SP>Air content>Grading of aggregate>Maximum size of aggregate; And the vertical deformation rate of SCC of a day has little connection with the static stability of SCC.The test result of the column test is sensitive to the GTM sieving test and the penetration test; Taking the test results of the column test and the GTM sieving test as reference, when the static stability of SCC is good, the upper value of the penetration depth could be adjusted to 7 mm; When the static segregation percent(mortar) is less than 12.8 %, SCC has a good static stability, and the mortar segregation percent and the static segregation percent are related linearly; Meanwhile, a longer flow time or a shorter slump flow mean a better static stability; and it’s a decreasing trend of the sensitivity of the flow time to the static stability of SCC from Tfin to T500; Besides SCC is considered to have a good static stability when at least three of the basic workabilities are satisfied, T500 between and including 5.3 s and 20.0 s, T600 between and including 12.1 s and 46.4 s, Tfin between and including 35.7 s and 63.7 s, the slump flow between and including 550 mm and 715 mm.