One of the main indicators of concrete quality is compressive strength. It is easy to see from the concrete strength expression that the compressive strength of concrete is proportional to the strength of concrete used for concrete. According to the formula, when the water-cement ratio is equal, the high-grade cement ratio is low. The concrete prepared with the label cement has a much higher compressive strength. In general, the water-cement ratio is inversely proportional to the strength of the concrete. When the water-cement ratio is constant, it is wrong to increase the cement strength to increase the concrete strength. At this time, the concrete workability can be increased, and the shrinkage and deformation of the concrete can be increased. .
Therefore, the main factors affecting the compressive strength of concrete are cement strength and water-cement ratio. To control the quality of concrete, the most important thing is to control the two main links of cement quality and concrete water-cement ratio. In addition, there are other factors that can not be ignored influencing the strength of concrete.
The coarse aggregate also has a certain influence on the concrete strength. Therefore, when the project starts, the technical person in charge first determines the coarse aggregate. When the stone strength is equal, the surface of the gravel is rougher than the surface of the pebble, and its adhesion to the cement mortar. Stronger than pebbles, when the water-cement ratio is equal or the same ratio, the concrete prepared from the two materials, the concrete strength of the gravel is higher than the pebbles. Concrete manufacturer
Therefore, we generally adapt the coarse aggregate size control of concrete to different engineering parts; the fine aggregate has less influence on the concrete strength than the coarse aggregate, but the quality of the sand also has a certain influence on the concrete quality. During construction, Strictly control the sand content of sand within 3%, therefore, the quality of sand and gravel must meet the requirements of the quality standards for gravel used for concrete.
Due to the relatively large changes in sandstone quality at the construction site, on-site construction personnel must ensure the quality requirements of sand and gravel, and adjust the water-cement ratio according to the moisture content of the sandstone in the field to ensure the concrete mix ratio, and the experimental ratio and construction can not be matched. More than a conflation.
At the same time, the quality of concrete is closely related to the type of admixture, the amount of admixture, and the way of incorporation. It is also one of the important factors affecting the strength of concrete. Concrete strength can only be guaranteed under normal conditions of temperature and humidity, and should be maintained in accordance with the construction specifications. The temperature of Luoyang concrete has a certain impact on the development of concrete strength. In the summer, it is necessary to prevent exposure to the sun, make full use of the temperature of the morning and evening temperatures to pour concrete; minimize the transportation and pouring time, prevent exposure, and increase the slump when the mixture is out of the tank; it is not suitable for intermittent watering during curing because concrete The surface rises in temperature when it is dry and cools when it is watered. This alternating heat and cold reduces the strength and crack resistance of the concrete. In winter, it is necessary to keep warm and prevent frost damage. In winter, the general heat storage method and steaming method are generally adopted. Kunshan Jianguo Concrete