The questions in large-scale canal wastewater treatment by using coagulation technique are introduced and their reasons were sought by coagulation experiments.

This article elaborated the status of concrete material in proje ct con struction and the development tendency of concrete technology, analyzed main exi stent problems in the concrete technology and the project development in Chongqi ng and put forward the interrelated proposal.

Application of dry concrete skill in old bridge maintaining;

In the mixproportion design of face slab concrete construction,the concrete crack control technology carries on the compensation to concrete expansibility,enhances the process control of concrete construction,and reaches the solution of transverse shrinkage crack of concrete slab of rock-fill dam produced by geometry size and external environment action.