Study On Impact Compression Properties Of Rubber-Modified Concrete For Non-Autoclaved Pipe Pile

PHC pipe pile,also called prestressed high strength concrete pipe pile,is an important construction component of pile foundation construction.Following the progress of modernization of construction industry in our country,the requirements for PHC pipe pile is increasing constantly,the performance and standard of PHC pipe pile are also improving.At present,the production of non-autoclaved concrete for pipe pile,its impact resistance is lower than that of autoclaved ones because of the elimination of the traditional high temperature and high pressure curing process.And in order to achieve the earlier strength properties of autoclaved concrete pile pressure,it was often added many admixtures in the mixture ratio such as slag,powder,silica beads,water reducing agent,while it can improve the peaceability and the durability of concrete,but the cost will be very large if directly put into the production.Before knowing the properties of concrete,it would be unwise to rush the PHC pipe products produced by the new process into the market.Especially,in engineering examples and scientific research,the failure rate of autoclaved pipe pile is higher than that of steam free pipe pile.So,the purpose of this study is aimed to mix a certain amount of the rubber powder to the pile pipe concrete and try to improve its defects of low toughness and poor impact resistance through the characteristics of the rubber flexible,deformation ability.In the process of study,we are familiar with the whole production process of pipe pile from material to finished product.Taking the autoclaved concrete pipe pile as the basis of concrete,to make of concrete test block of different amount of rubber powder,and all concrete blocks are stirred,molded and maintained with the same batch of pipe piles under the same condition.Through the static compression test of concrete and the SHPB bar impact test,the influence of rubber powder on the static compressive strength of tubular concrete and some mechanical properties of rubberized concrete are studied.Through the experimental results and theoretical analysis,it is found that the effect of rubber powder on the static compressive strength of concrete is mainly due to the change of interfacial strength of the internal structure of concrete,static compressive strength of rubber concrete will decline as the amount of rubber powder added.The form of failure of rubber concrete under static compression condition is also very different from that of ordinary concrete.The performance of rubberized concrete under high strain rate loading was studied by SHPB pressure bar impact test.The performance of rubberized concrete under high strain rate loading was studied by SHPB pressure bar impact test.In the form of damage,with the increase of strain rate,the failure of rubber concrete is changed from cracks to fractures.Reflecting the dynamic enhancement effect,the rubber concrete is the same as the ordinary concrete,its dynamic compressive strength is higher than the static compressive strength,Its change rule related to the impact velocity and energy,also is closely connected with rubber content.Rubber powder can improve the deformation properties of concrete and the energy absorption effect of rubber concrete is higher than that of ordinary concrete.These results provide a reference for the study of the performance of the autoclaved tubular pile and of rubber modified concrete.