Microexpanded ultrahigh-performance concrete and preparation method

Abstract

The invention discloses micro-expanded ultrahigh-performance concrete and a preparation method. The concrete is prepared from the following ingredients in parts by weight: 100 parts of Portland cement, 10 to 55 parts of mineral additives, 20 to 60 parts of silicon ash, 10 to 35 parts of volume stabilizers, 150 to 250 parts of quartz sand, 15 to 40 parts of steel fiber, 2.0 to 5.0 parts of high dispersion and low viscosity type water reducers and 30 to 45 parts of water. The micro-expanded ultrahigh-performance concrete replaces a negative bending moment region conventional mechanical tensioning prestress structure to form a non-prestress simple support rotation continuous system; the self-bearing force, interface bonding, micro-expanded expansion performance and durability requirements canbe met; the construction efficiency of the non-prestress simple support rotation continuous system bridge is effectively improved. The concrete has the ultrahigh pressure-resistant and tension-resistant intensity, ultrahigh durability, micro expansion performance, steam curing avoidance, bonding performance and reasonable economic performance; meanwhile, good construction performance is realized.

Description

technical field [0001] The invention relates to the field of highway bridge engineering and building materials, in particular to a micro-expansion ultra-high performance concrete and a preparation method thereof. Background technique [0002] Usually, in the bridge structure with a basic span of 30m and then simply supported and then continuously prefabricated T-beam construction, the continuous beam is formed by setting the cast-in-place section on the top of the pier and tensioning the negative moment steel tendon by mechanical tensioning. Prestressing is used to resist the tensile stress on the upper edge of the negative moment zone at the top of the pier, preventing concrete from cracking or reducing the crack width. However, this method requires high technology, equipment, personnel and management, and the construction is relatively cumbersome, which increases the workload and difficulty of construction, and affects the scheduled use of the bridge. Therefore, if a kind...

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Problems solved by technology

[0003] The technical performance of ordinary high-performance concrete (compressive strength ≤ 60MPa, tensile strength ≤ 5MPa) can no longer fully meet its needs, so it is necessary to develop an ultra-high performance concrete material (compressive strength ≥ 150MPa, tensile strength ≥ 25MPa) To meet the aforementioned engineering technical needs

Although the current ultra-high performance concrete has been demonstrated and applied in engineering, there is still a long way to go before large-scale promotion. It mainly has the following problems: 1) ultra-high performance concrete shrinks greatly and is easy to crack; 2 ) The construction of ultra-high performance concrete is difficult, and its components are not easy to disperse; 3) The cost of materials is too high, and the cost of engineering projects is greatly increased

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