High-strength steel bar enhanced engineered cementitious composites (ECC)-hollow steel pipe ultra high performance concrete (UHPC) combination column member and manufacturing method thereof

Abstract

The invention relates to a high-strength steel bar enhanced engineered cementitious composites (ECC)-hollow steel pipe ultra high performance concrete (UHPC) combination column member and a manufacturing method thereof, which are particularly applied in the field of pier column members with high-rise, overload and long-span structures. The member comprises ECC, a steel bar framework poured in the ECC, a steel pipe, UHPC poured on the inner wall of the steel pipe and a cavity. By the member and the method, the advantages of the ECC, a high-strength steel bar and the UHPC of a hollow steel pipe are integrated, so that respective advantages can be fully exerted, the problem of corrosion of the steel pipe and the steel bar is well solved, the durability of the member is effectively improved, the life cycle of the member is prolonged, and later-stage maintenance and reinforcement cost is reduced; and the member is high in bearing capacity, drawability, shock resistance and fatigue resistance. By a partial prefabrication production and partial on-site pouring construction method, the quality of the member can be easily ensured, a prefabricated part can be directly used for constructing an upper structure of a bearing member support, the increase of a construction speed is facilitated, and a construction cycle is shortened.

Description

Technical field [0001] The invention is a high-strength steel reinforced ECC-hollow steel tube UHPC composite column component and a manufacturing method, and is particularly suitable for the field of high-rise, heavy-load, and large-span pier column components. Background technique [0002] Ultra-high toughness fiber-reinforced cementitious composites (Engineered Cementitious Composites, referred to as ECC) is to remove coarse aggregates, optimize the basic properties of the matrix, fibers and the interface between the fiber and the matrix, and the interaction between the three, so that it has high resistance A new type of cement-based composite material with cracking, high toughness and high energy absorption capacity. The ultimate compressive strain of ECC materials can reach 0.5%-0.7%, which is about 3 times that of ordinary concrete; the ultimate tensile strain can reach more than 3%, which is more than 300 times that of ordinary concrete; what is especially prominent is its...

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Problems solved by technology

The use of high-strength steel bars will bring good economic and social benefits, promote the technological progress of the construction industry, and save a lot of energy, electricity, transportation and processing costs, reduce the emission of smoke, dust and pollutants, and promote the upgrading of steel bar products Upgrading, reducing resource consumption, and promoting technological progress are in line with the concept of environmental protection and sustainable development, but due to insufficient promotion and immature research results, they are rarely used in China

[0005] Reinforced concrete columns have the following defects in the face of heavy-load and long-span structures: due to the low strength of concrete and steel bars, in high-rise and long-span structures, the load is relatively large, and the only way to increase the size of the column section and to increase the reinforcement The method of improving its bearing capacity not only causes a great loss of materials, increases the construction cost and construction difficulty, but also seriously compresses the available space; the tensile strength of concrete materials is low, and the tension zone has cracked under lower loads, and Cracks appear in the form of wide main cracks. Excessive cracks not only reduce the rigidity of the column, but also cause the internal steel bars to corrode easily, reducing the bearing capacity and durability, making future maintenance difficult and costly

If high-strength steel bars are used, due to the small ultimate compressive strain of concrete, the high-strength steel bars have not yet yielded when the concrete is crushed, and the role of high-strength steel bars cannot be fully exerted, and the ductility of the components is seriously insufficient, resulting in brittle failure without symptoms

[0006] Concrete-filled steel pipe columns, no matter what kind of concrete is used inside, including UHPC materials, can partially avoid the above defects, but the substructure where the columns are usually located in a humid environment with many bad media, and steel pipes are prone to corrosion, and it is difficult to repair and replace once a problem occurs , and the daily maintenance is frequent and the maintenance cost is high

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