Based on the foundation of heat conduction equation, this paper analyses the Yellow River bridge liujiaxia anchorage of mass concrete temperature field and stress field in the natural cooling and stratified pouring time interval for 7 days to circumstances with the MIDAS/CIVIL finite element software. The results show that the interval 7 days stratified pouring and natural cooling method, can't meet the requirements of concrete anti-crack.

Bonding quality is the key factor that affects the safety of concrete-filled steel tube (CFST) structure, so it is a very important research that how to judge the bonding quality. This paper expounded the theory of three methods used in nondestructive testing of CFST, and introduced the combined application of the methods of artificial tapping, ultrasonic testing, and strain analysis in a large simulation test.

This text, under the guidance of PID control algorithm, designs and implements a new type of solar water heater which can change orientation of its solar panel in real time to automatically follow the direction where the light is strongest by sensing the incident angle of the sun. Tests show that the new solar water heater can succeed in keeping a real-time trace of light source, which can effectively meliorate the traditional solar water heater's shortcoming of producing insufficient heat in winter in some areas and greatly improve the utilization efficiency of solar energy.

Concrete valuation work is mainly on the composition of concrete raw material pricing, different concrete mixture ratio has decisive influence on the valuation. Concrete mix is influenced by many parameters, such as water-binder ratio, sand percentage, unit water and so on. The mixture ratio is the purpose to research the inner relationship between concrete parameters.In the preparation of the consumption of the concrete norm, analysis to the reasonable mix can not only make valuation work accords with the specification requirements, but meet the practice.