Effect Of Reactive Powder On Shrinkage Resistance Of Cement Stabilized Crushed Stone

Cement stabilized crushed-stone is one of the commonly used materials in the highway base in China.It provides to be a stable and solid working face for the surface structure,as well as regulating and improving the hydrologic status of the pavement structure.However,the cement stabilized crushed-stone is prone to crack during the useing process,which has become an urgent problem to be solved in the road base structure of our country.This article attempts to improve the anti-cracking performance of cement stabilized macadam by adding active powder(fly ash and granulated blast furnace slag powder,single and composite).Meanwhile,the effect of adding active powder on the road performance of cement stabilized crushed-stone,such as mechanical properties and anti-erosion properties,was studied,In order to provide technical support and reference for the application of active powder in cement stabilized crushed-stone base layer.Through the unconfined compression test and indirect tensile test of cement-stabilized macadam,combined with XRD microscopic phase analysis,the influence of active powder on the mechanical properties of cement stabilized macadam was studied.The results show that the fly ash and granulated blast furnace slag can improve the mechanical properties of cement crushed-stone,and the strength of cement crushed-stone with granulated blast furnace slag is increased rapidly,and the mechanical properties of composite active powder cement crushed-stone are the best.According to the test results of mechanical properties,the correlation of shrinkage properties of cement crushed-stone was studied by the dry shrinkage test of cement stabilized macadam and the temperature shrinkage test.The results show that using active powder can improve the shrinkage properties of cement crushed-stone.Fly ash and composite active powder improve the dry shrinkage performance of cement crushed-stone;granulated blast furnace slag improves the temperature shrinkage performance of cement crushed-stone in high temperature range.Composite active powder improves the temperature shrinkage performance of cement stabilized macadam at normal temperature and low temperature range;composite active powder is considered to contractile cement crushed-stone,witch can be improved the best.Meanwhile,8 groups of mixtures were selected to study the scouring resistance of cement crushed-stone.The results show that adding active powder can improve the anti scouring performance,and the composite active powder can improve the anti scouring performance of cement crushed-stone,and the strength of cement crushed-stone with high cement dose is relatively high,which is beneficial to improve the anti scouring performance.In order to verify the results of this study,combined with the specific local conditions in Maoming,Guangdong,the experimental road was paved on the Sha nzhan Expressway in 2017,and the tracking observation was carried out.The related research results were further studied,and the related experience was also accumulated for the field construction and crack resistance improvement technology.