Steady inflated steel tube concrete and construction method

Abstract

The compound contains water, cement, sand material, flyash. The characteristic is that it also contains compound high-efficiency water-reducing mould-protecting agen, cement is aluminate sulfide cement 500-550, flyash 50-55, water 185-195, compound high-efficiency water-reducing mould-protecting agent 11-15, weight sand ratio of sand material is 38-42 percent. the compound high-efficiency water-reducing mould-protecting agent is composed by naphthalenes high-efficiency water-reducing agent, boric acid and xylon calcium sulphonic acid, weight percentage of each compound are azyl sulfonate high-efficiency water-reducing agent 32-38, nephthalenes high-efficiency water-reducing 37-43, boric acid 12-18, xylon calcium sylphonic acid 7-13.

Description

technical field [0001] The invention belongs to the field of building materials, and in particular relates to a steel pipe concrete and a construction process thereof. Background technique [0002] Because the steel pipe concrete structure has the characteristics of large bearing capacity, significant economic benefits, beautiful appearance, convenient construction and guaranteed construction quality, so this composite material is more and more widely used in modern building structures. The combination of steel pipes and concrete in steel pipes can give full play to their strengths and obtain excellent mechanical and structural properties. But one of the prerequisites is that the steel pipe wall and the concrete inside must be closely combined, and the steel pipe must have a tight force on the core concrete. In order to achieve this purpose, expansion agents are usually added to concrete components such as Portland cement, coarse and fine aggregates, etc., to cause a chemic...

AI Technical Summary

Problems solved by technology

[0003] 1. Calcium silicate gel and other substances are formed after Portland cement is hydrated, which is prone to chemical shrinkage and plastic shrinkage; thus resulting in a decrease in expansion stress and affecting the expansion performance of the expansion agent;

[0004] 2. The expansion agent needs to undergo a chemical reaction with the hydration product in the Portland cement hydration system to produce expansion. This process is not easy to be consistent with the strength development of concrete

[0005] 3. Most of the concrete in the steel pipe concrete structure is high-strength, high-performance concrete; most of them are mixed with mineral admixtures, chemical admixtures and other substances, and the components are complex. It is easy to omit, add or add certain components during on-site construction. ; If the above phenomenon occurs in the construction with the expansion agent, it will affect the close combination between the concrete and the steel pipe, and even lead to the destruction of the steel pipe concrete structure and cause a major accident;

[0006] 4. During the construction of concrete-filled steel pipe structures, especially long-span and large-diameter concrete-filled steel pipe arch bridges, in order to maintain structural stability, it is generally necessary to shut down for a period of time after pouring a steel pipe to make the poured concrete reach more than 80% of the design strength. The pouring construction of the next steel pipe can only be carried out after the bearing capacity is reached, and the construction period is longer

The main reason is that in order to make the concrete filled steel tube compact, pumping jacking is generally used for construction. Due to the short setting time of sulphoaluminate cement (initial setting 10-20 minutes), the slump loss of concrete prepared with this cement is large over time, which cannot meet the requirements. Construction requirements