In order to solve the shortcomings of shrinkage of concrete, at home and abroad has developed a alunite expansive agent, anhydrous calcium sulfate expansion agent, lime expansion agent and calcium aluminate expansion agent. Concrete expansion agent is developed on the basis of the expansion of cement, so that after the hardening of the concrete to produce a certain volume of expansion, reduce the concrete hardening of the early shrinkage of concrete cracks. Long-term studies suggest that sulfur-aluminum compounds, calcium oxide and magnesium oxide can act as chemical constituents of expanded cement or concrete, but from controllable expansion and chemical stability, from the perspective of compensatory shrinkage and objectivity to produce greater self-stress In terms of domestic and foreign advocates calcium alum as the main hydration products of sulfuric aluminate as expansion agent.Road Repair Machines
The deformation of the two particles in the material (compression) will not crack; back deformation (tension) will cause cracking, it is inferred that the concrete free shrinkage will not crack, limiting shrinkage will cause cracking; concrete expansion will cause cracking, Expansion does not cause cracking. The relationship between deformation and cracking of concrete determines the expansion intensity of expansive concrete (EC) during hydration hardening. In addition, the expansion of concrete or compensated shrinkage of the concrete only in the restricted conditions of the compensation contraction in order to improve the early strength, improve the density, delay due to shrinkage caused by cracking time, smooth through the early low tensile strength, easy to crack the dangerous period, thus Improve the ability of early crack resistance; the other hand, delay the possible cracking time, so that the concrete strength to further improve, to avoid or reduce the purpose of concrete cracking.
The addition of expansion agents gives us a better understanding of high performance concrete, from high-strength concrete to high-performance concrete (HPC) today. HPC is a new type of high-tech concrete, is a substantial increase in the performance of ordinary concrete on the basis of the use of modern concrete technology, the use of high-quality raw materials, in strict quality management made of high quality concrete. It must meet the general performance of ordinary concrete, but also must meet the high strength, high mobility, high volumetric stability, high environmental protection and excellent durability and other requirements.construction machine shake the hand wheelwholesale asphalt crack sealing materialsroad crack sealing material