Table of Contents
The problem of concrete cracks is a practical problem that is ubiquitous and difficult to solve. In this paper, the causes of some cracks in concrete engineering are analyzed from the aspects of design, material, mix ratio, construction site maintenance and so on. According to the causes of concrete cracks, the measures to control the development of cracks are put forward in the aspects of concrete structure design, concrete material selection, mix proportion optimization and maintenance of construction site. According to the relevant literature, and summarizes the treatment methods of concrete cracks: surface treatment method, filling method, grouting method, structural reinforcement method, concrete replacement method, electrochemical protection method, bionic self-healing method and so on.
Solar energy as a huge amount of renewable energy, the daily arrival of the earth's surface radiation energy equivalent to hundreds of millions of barrels of oil burning energy. Development and use of rich, vast solar energy, cannot produce or produce little pollution to the environment, solar energy is both the urgent need for future energy supplement, but also the basis of future energy structure. However, because the traditional do not pay much attention to the collocation of PV modules, resulting in a lot of waste, this paper presents a new optimization design method for the shortcomings of the previous system design methods. This paper summarizes the composition and operation of the PV system, and discusses the establishment of the mathematical model of each part. Including the solar radiation resource model, the best tilt model of the solar cell matrix, the solar cell square power generation model, the battery status model, the load model. On the basis of this, the paper takes the minimum energy loss of PV system as the principle, and studies the problem of maximum power point tracking and the selection of inverter circuit, which has certain practical application value
Roof waterproof engineering is an important part of architectural engineering, waterproof engineering quality is good or bad, a direct impact on the life of buildings and structures, affecting people’s normal life order. “The Construction Engineering Quality Management Ordinance” provides for the roof waterproof engineering warranty period of 5 years, showing that the quality of roofing works is an important part of the civil housing construction. Its main role is to meet the user on the housing drainage, waterproofing, heat insulation, thermal insulation requirements. Roof cannot have leakage and water phenomenon, while the roof should also make the roof after the landscaping function. Roof construction quality is good or bad, the pros and cons are related to the life of the building. If the roof of water leakage, water seepage, people will bring a lot of inconvenience to life, not only cause serious economic losses, but also directly affect the people's normal life. So to ensure the quality of roof engineering, design is the premise, the material is the foundation, construction is the key, and maintenance management is guaranteed. Only the strict material off, well-designed, carefully construction, in order to ensure the quality of roofi ng works in order to give users to create a good living or working environment.
Prediction of residual strength of structural members in a RC fire-damaged building is an important step in taking a decision about restoration or demolition of the building. In this paper a finite element model was developed to evaluate the distribution of temperature within the cross-section of a RC column during a fire. Then the results were used to estimate the residual strength of RC columns in a fire damaged building in Libya. The building was used as a court yard for the public and the fire visibly damaged some of its columns. Material tests were conducted in situ and in the laboratory in order to evaluate the material strength after fire. Finite element analysis results and Euro code formulations were used in the prediction of material properties during fire .The predicted properties shows good agreement with material test results. Furthermore analysis results shows that up to 60 min of fire duration the column do not lose considerable amount of its strength, however at 120 min fire duration it will lose about 35 percent of its axial load and moment carrying capacities.