Preparation And Properties Of Sulphoaluminate Cement-based Material Blanket

Traditional concrete is the most commonly used repairing material in the maintenance of old cement pavement,but it has some technical bottlenecks,such as low pre-strength,delayed open traffic,frequent secondary damage and complex construction process.Based on three-dimensional spacing fabric mesh and super early strength sulphoaluminate cement-based material powder,a sulphoaluminate cement blanket with excellent fatigue resistance,high strength and early strength was developed.The main research contents include:(1)The 42.5 grade sulphoaluminate cement was modified and its optimum mix ratio was obtained by single factor analysis,orthogonal test and range analysis.The properties of fresh paste and hardened paste were studied.The results show that the compressive and flexural strength of the modified sulphoaluminate cement matrix material reaches 39.8 MPa and 6.2 MPa in one hour,103.1 MPa and 10.7 MPa in 28 days and 0.020%and 0.034%in 7 and 60 days respectively.It has the advantages of fast hardening,early strength,high strength,corrosion resistance,volume stability and good cohesion.It meets the performance requirements of cement blanket for matrix materials.(2)Three dimensional spacer fabric was used as carpet body and Modified Sulphoaluminate Cement as filler material.After filling density calculation and water consumption test,cement blanket with water curing was obtained.The bending strength,tensile properties,impermeability and skid resistance were tested and analyzed.The results show that the flexural strength of 25.9MPa can reach up to 2.2;the impermeability of 800Pa under water pressure reaches up to the standard value(24h);the transverse and vertical swing values are 75.4BPN and 73.4BPN respectively.It shows that it is a new road material with good flexural performance,good impermeability and good skid resistance.(3)The construction technology of repairing with cement blanket is studied;the stress diagram of different working conditions is analyzed by ANSYS simulation software;based on the cost analysis of maintenance company,the economy of repairing the pit is compared and analyzed.The cost of repairing the pit with a depth of 4 cm is 99.85 yuan/square meter,which is 20.08%less than that of traditional concrete repairing.The results show that the use of cement blanket can greatly simplify the process,improve efficiency and save costs,and has better stability than ordinary concrete,and is less prone to damage.In summary,sulphoaluminate cement blanket was characterized by convenient and green construction,high time-saving prior to traffic reopening,low comprehensive cost and excellent fatigue resistance.Consequently,it could satisfy the needs of efficient and green maintenance of cement concrete pavement.