High-strength concrete structure without cracking can achieve high performance
High-strength concrete has a low water-binder ratio and a large amount of cementitious materials, which leads to an increase in hydration temperature, so plastic shrinkage and self-shrinkage. Although high-strength concrete has a higher tensile strength, it has a high elastic modulus, which will cause higher tensile stress under the same shrinkage and deformation, so the risk of cracking in the early stage and during use cannot be ignored.
The concept of large cementitious materials
Cementitious materials are no longer the sole or absolute component of cement, but are composed of cement and admixtures, and admixtures do not necessarily have activity.
At present, the definition of cementing materials in many of our standards basically refers to cement and mineral admixtures; and our definition of admixtures includes inactive mineral powders, so inactive admixtures should be gelling One of the material components. Large cementitious material means that the powder is the cementitious material. Otherwise, the corresponding relationship between our water-binder ratio and strength will be difficult to maintain.
High-strength and high-performance concrete based on high-quality aggregate
Concrete Coarse Aggregate Amount
The amount of coarse aggregate is an important indicator to measure the high performance of concrete. Too high sand rate is unfavorable to the volume stability of concrete structure.
High-strength concrete should also pay attention to the ratio of grout to bone. Under the premise of ensuring good construction performance, more use of aggregates and effective control of slurry and water consumption are one of the technical principles for high-strength concrete to pursue high-tech energy.
The concept of high-quality aggregate
The high quality of aggregate includes character and quality, such as particle size, particle shape, gradation, firmness, water absorption and other main technical indicators are better than the existing national standards for Type I sand and stone requirements to meet the requirements of high-performance concrete mixtures. Under the premise of good construction performance requirements, control a lower grout-to-bone ratio to stabilize the volume of concrete, reduce cracking sensitivity, and meet durability requirements.
Don’t think that coarse aggregate is not important
Coarse aggregate is the upstream of the concrete preparation technology, that is to say, the concrete preparation starts with piles of rocks.
Making artificial sand well is the core issue
Whether we like it or not, we must face a new era of using artificial sand for construction. There are many artificial sand problems. The key is that the gradation problem, the particle shape problem and the stone powder problem have not been solved properly. The quality of artificial sand directly affects the wide application of high-strength concrete in large flow, and it is a problem that must be solved.
Contact us to get the output, technology and latest quotation of the artificial aggregate plant.
Configuration and performance concept of high performance concrete
The viscosity of ready-mixed concrete should have a suitable range. It should not be low-strength, high-strength
Oligo water. That is to say, high-strength concrete should not be too thick, and low-strength concrete should not be too thin.
Do not use too much high-strength concrete cementitious material, and low-strength concrete cementitious material
The material should not be too small; this is beneficial to the homogeneity and volume stability of the concrete.
Shrinkage of high-strength and high-performance concrete
The shrinkage value of concrete should be another important control for the performance of high-performance concrete Indicators, whether the shrinkage value can be controlled to three to ten thousandths or lower is the direction of efforts. It is even more challenging for high-strength concrete.