Properties And Construction Technology Of Concrete In Shouguang Waterworks Project

With the economic development and improving living standard,people have more requirements for the quality of drinking water.Therefore,it becomes increasingly urgent for the water supply industry to set down higher standards for water purification in order to meet people's increasing need for higher-quality water.The project of utilization of surface water for the central water supply of Shouguang City is located in the city of Shouguang,Shandong Province.It is an important livelihood project to guarantee the safety of the water supply for both urban and rural areas,to protect the resources of the underground water,and to facilitate the sustainable development of the society and economy.The designed project service life is 50 years,with a daily capacity of 100,000 m3/d and a cost of RMB 137 million.Based on this project,this thesis studied the mix proportion factors of concrete,the construction scheme and techniques of concrete and the function of the concrete structure after the construction.Firstly,the influence of mix proportion factors on the properties of concrete was studied by experiments,which provided reference for the mix design of Engineering concrete.The effect of water-binder ratio,expansive agent content,fly ash content,sand ratio and cementitious material content on the workability,compressive strength and impermeability of concrete was investigated,and the results showed that the slump of fresh concrete increased with the increasing of water-binder ratio,fly ash content and cementitious material content,and decreased with the increasing of expansive agent content.The compressive strength of concrete at 7days and 28 days droped with the increasing of wat er-binder ratio and fly ash content,and it rised firstly and then decreased with the increasing of expansive agent content.The impermeability of the concrete was improved by adding proper dosage of expansive agent,and increasing fly ash and cementitious material content,while the effect of sand ratio is relatively minor.Based on the features and requirements of high walls and floors in the waterworks,the study of construction techniques was carried out,and the construction scheme and techniques were summarised.Four main measures were employed or improved in the construction.The positioning wooden box of rubber water proof belts improved the installment quality,overcoming the flaw of leakage in the traditional techniques of water proof belts.The ap plication of three-stage removable tension bolts solved the problem of leakage of concrete structure caused by hole of connecting rod bolts and the lack of durability of concrete structure caused by the corrosion of connecting rod bolts.The curing system of water spraying on concrete walls and drip curing method for frame columns improved the curing effect of concrete,which was also significant for the water conservation.At last,the performance of concrete was tested to verify the effectiveness of construction scheme and techniques.The impermeability and compressive strength of the reserved concrete specimens after construction revealed that the properties could meet the designed standards.The full wate test of the water storage concrete structure showed that the water seepage of 24 hour was lower than the designed limit and the concrete structure has good impermeability,which indicated that the materials,mix proportions and construction techniques were effective in this project.