Super-rapid hardening cement concrete

Abstract

The invention relates to a super-rapid hardening cement concrete which is characterized by comprising a cementing material, sand, gravel, a water reducing agent and water. The cementing material is composed of P.II 52.5R Portland cement, pure-sulfur aluminate cement, gypsum and activated silica powder. The super-rapid hardening cement concrete also comprises a setting accelerator or setting retarder; and the water reducing agent is a polycarboxylic acid water reducing agent. The sand adopts natural river sand in which the silt content is about 0.5%. The gravel adopts continuous-grade shaped stone. The setting accelerator is a lithium salt setting accelerator, and the setting retarder is a tartaric acid setting retarder. The concrete prepared according to the invention has high early strength, and the strength can reach 30 MPa above within 3 hours at the most. The concrete has stable later strength, and the strength can reach 40 MPa above within 24 hours and reach 50 MPa above after 28 days. The concrete has stable performance, and the price is only 2 / 3 or so of the imported product since most materials are national materials.

Description

technical field [0001] The invention relates to the field of concrete materials, in particular to an ultra-fast hardening cement concrete and the cementitious material used therein. Background technique [0002] Since the 1980s, with the rapid development of the national economy, the mileage of expressways and urban expressways has continued to extend, the speed of roads has continued to increase, and the transportation industry has risen sharply. Several times the pressure, many structures have been damaged. If they are not repaired in time, there will be serious accident hazards and even endanger public safety. my country's large-scale construction has lasted for nearly two decades, and is about to enter the era of simultaneous large-scale construction and large-scale maintenance. Road maintenance will inevitably affect traffic capacity, especially the already congested urban traffic; in the confusion of congestion and repair, how to minimize the impact on traffic, the co...

AI Technical Summary

Problems solved by technology

Therefore, sulphoaluminate cement is used less and less as a structural material, and it is only used in emergency repairs and other emergency situations, and in most cases it can only be used as a temporary measure

[0005] Second, the lack of research

[0008] In fact, in today's fast-growing China, in addition to rapid maintenance of roads and bridges, there is also a great demand for rapid concrete in other fields. How to solve the problem? The quality of domestic rapid concrete cannot meet the requirements of use, and the quality of foreign materials is good. But the price is high, especially if the international situation changes suddenly, and others will not sell it to you, what should you do? In order to get rid of the current dilemma of ultra-rapid hardening concrete, it is urgent to solve the technical bottleneck of ultra-rapid hardening concrete, and independently develop high-quality, cost-effective ultra-rapid hardening concrete to meet the growing domestic requirements

Images