Prestressed concrete constructing process for curved shape memory alloy tendon

Abstract

The invention discloses a prestressed concrete constructing process for a curved shape memory alloy tendon. The constructing process specifically comprises the following steps: a plurality of curved shape memory alloy tendons are embedded into a template along the length direction of the concrete, and two ends of each tendon are allowed to respectively penetrate through and extend out of the template; the concrete is poured in the template and integrally formed along with the curved shape memory alloy tendons; after the concrete strength reaches above 75%, the shape memory alloy tendons are in batches or gradually heated by adopting an electrothermal method, after the shape memory alloy tendons are gradually heated to appointed temperature, the shape memory alloy tendons generate the one-way shape memory effect, so that the lengths of the shape memory alloy tendons trend to be reduced to a primary memory alloy tendon shape, and the concrete generates a certain constraining force so as to generate the prestress. According to the constructing process, the crack resistance, rigidity, durability and application scope of a prestressed structure is improved, and thus the purpose of applying the prestress to the concrete can be achieved, the constructing process is simple, convenient to operate, and safe and reliable in effect.

Description

Technical field [0001] The invention relates to a construction process of curved shape memory alloy bar prestressed concrete, which belongs to the technical field of building structures. Background technique [0002] Modern buildings are developing in the direction of large-span, light-weight, high-performance and other diversification. The form of the structure and the materials used must also be diversified. The use of prestressed concrete structures is undoubtedly an effective way to achieve this direction. The development of prestressed concrete structures to today is not only widely used in traditional fields such as bridges, building construction, pavements, sleepers, piles, pressure vessels and storage tanks, but also widely used in civil engineering, special structural engineering, reinforcement engineering, In many new fields such as energy engineering and ocean engineering. [0003] As an important parameter of prestressed concrete structure, the key indicators of prestr...

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Problems solved by technology

[0003] As an important parameter of prestressed concrete structures, the key indicators of prestress, construction technology and equipment requirements controlled by it have always been three difficulties in the field of engineering technology. If the applied prestress size and method do not meet the requirements, it is difficult to obtain enough High crack resistance and rigidity; if the construction process is more complicated, the required personnel team skills are more skilled, and the cost is higher; if the construction equipment is heavier, the start-up cost is higher, and the work is also easily restricted by the environment

Traditional prestressed concrete components mainly include pre-tensioned prestressed concrete structure and post-tensioned prestressed concrete structure. These two structures have some defects, specifically: It requires a large investment cost, and at the same time, the pedestal can only be fixed in one place, which is not flexible enough, and can only produce medium and small prestressed linear components; post-tensioned prestressed concrete often cannot be prestressed at the same time, resulting in more processes and poor craftsmanship. Complexity, increased equipment functions, cumbersome operation, especially the large amount of steel consumption for the required anchorage, high precision anchorage processing requirements, resulting in expensive costs, and must reserve holes, hole grouting and other disadvantages

In short, the above two traditional prestressed concrete components have the disadvantages of high equipment requirements, complicated construction technology, high prestress loss, high requirements for controlling prestress, low steel plasticity and corrosion resistance, etc., especially for curves or These deficiencies are particularly prominent in the construction of prestressed structures in the shape of broken lines

Therefore, it is difficult to achieve suitable prestress control, simple construction technology and equipment, and wide application range for the construction effect of prestressed concrete structures made of traditional materials by pretensioning or posttensioning.

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