Study On Rapid Prefabrication And Assembly Of Concrete

Cement concrete pavement has been developing for more than 30 years in our country.With the continuous development of traffic,the requirement for the performance and speed of concrete pavement is also increasing.Along with the maturity of municipal roads and highways,the problems caused by closed traffic construction are bigger and bigger.At this time,the advantages of rapid precast and assembling process,fast traffic and excellent quality of cement concrete pavement are presented.However,in the practical application,the lack of domestic experience and some inherent problems restrict its development.Based on this kind of environment,starting from the initial process of plate division and design,aiming at the angle shaped plate at the intersection(non rectangular plate)problems summed up the experience in recent years abroad,and combining the domestic construction status,gives a complete recovery with corner corner stitching and hexagonal plate rectangular plate butt at the lane by theoretical analysis,and feasibility.On the other hand,from the similarities and differences between the prefabricated and the traditional cast-in-place construction,based on the common failure mechanism of cement concrete pavement,the pavement structure layer is discussed,and the method of adding the 2mm~3mm bitumen crushed stone to the bottom layer between the surface layer and the base is put forward.Through the Ansys finite element modeling,the stress settlement of the plate side angle is still larger after adding additional layer,and the proposed surface layer modulus is 38000 MPa or slightly higher,and the thickness of the surface layer is about 24 cm.Based on this,the use of lightweight high-strength concrete is analyzed and hoisting analysis is carried out.Based on the demand of light and high strength,the concrete mix ratio was designed,and the requirements of strong cohesiveness,good integrity after forming,C90 marking and 8MPa flexural strength were put forward in the mixing process,and it was realized through indoor test.Under the condition of controlling the water binder ratio and water reducing agent,and the proportion of fly ash and mineral powder 35%,with the decrease of fly ash and mineral powder,the strength of 7D first decreases and then increases,and the trend of 28 d strength is opposite to that of 7D.The amount of fly ash should be controlled between 10~15%,and the corresponding amount of ore powder should be controlled between 25%~20% and higher compressive strength and flexural strength at the same time.Therefore,this paper from the aspects of intersection plate disposal scheme,design of pavement structure and pavement drainage design,concrete materials,assembling prefabricated construction technology of regression,to a precast cement concrete slab based on the analysis of the key points and problems of each step in the construction of the proposed control requirements.