Using machine-made sand instead of quartz sand,low carbon,environmental protection and relatively low cost UHPC can be prepared.The application of machine-made sand UHPC in class A manhole cover structure has the characteristics of high strength,high toughness,high abrasion resistance and high durability,and it is free of reinforcement process,high construction efficiency and late maintenance free,which has good engineering application prospect.In this paper,the proportion design and basic mechanical properties of machined sand UHPC are studied,and the model test,numerical simulation calculation and economic benefit analysis of machined sand UHPC manhole cover without reinforcement are carried out.The results show that with the increase of water-binder ratio,the compressive strength and elastic modulus of UHPC decreases gradually,and the tensile strength increases first and then decreases.When the content of stone powder increases gradually,the compressive/tensile strength and elastic modulus increase first and then decrease.With the increase of fineness modulus and steel fiber content,the compressive/tensile strength and elastic modulus are improved,but the increase amplitude is gradually slow.When steel fiber is not added,the manhole cover exhibits brittle failure.When steel fiber is added,the overall stiffness and ductility of the manhole cover are increased due to the significant crack resistance effect of steel fiber,showing obvious elastic-plastic failure characteristics.With the increase of steel fiber,the crack load and failure load of manhole cover increase gradually,but the increase amplitude gradually becomes slow.Compared with traditional UHPC manhole cover,ductile iron manhole cover,ordinary steel fiber concrete manhole cover,the cost of UHPC manhole cover without reinforcement mechanism sand can be saved by 11％～66％;The design parameters of 20mm thickness,400mm～600mm diameter and 2％steel fiber content can be adopted for UHPC manhole cover without reinforcement mechanism sand to meet the force requirements of class a manhole cover.
machine-made sand of UHPCmanhole coverwithout reinforcementmechanical performancenumerical modelingeconomy
国家科技期刊平台
NSTL
维普
万方数据
