Ultra-high performance concrete for expansion joint transition area and preparation method thereof

Abstract

The invention discloses an ultra-high performance concrete for an expansion joint transition area. The ultra-high performance concrete is prepared from the following main raw materials: cement, fly ash microbeads, silica fume, high-titanium heavy slag sand, organic-inorganic hybrid fiber, a waterborne epoxy emulsion, a water reducing agent and water. According to the invention, the high-titanium heavy slag sand is used as aggregate, the internal curing and pin effects of the aggregate are utilized to improve the volume stability, anti-permeability and cracking resistance, and mechanical properties of the concrete; an organic-inorganic fiber composite toughening technology is adopted to enhance the bending toughness and impact resistance; the water reducing agent and fly ash microbeads areadded to improve the working performance and compactness; and the obtained ultra-high performance concrete has the advantages of high flow state, low shrinkage, high toughness, high adhesion, high impact performance, fatigue resistance and the like, can fundamentally solve the problems of repeated repairing, repeated damage and the like of concrete in expansion joint transition areas, and has important practical application value.

Description

technical field [0001] The invention belongs to the field of building materials, and in particular relates to an ultra-high-performance concrete in an expansion joint transition zone and a preparation method thereof. Background technique [0002] At present, most of the bridge pavements in China use asphalt mixture for bridge deck paving, and cement concrete is used to fill bridge expansion joints. Therefore, the quality and flatness of the concrete in the transition zone of expansion joints directly affect the life of the bridge and the driving comfort. On the one hand, because it directly bears the repeated rolling impact of the wheel, the concrete in the transition zone has high rigidity and poor deformation capacity, and cannot effectively absorb and transmit the impact energy of the expansion body; on the other hand, it has been exposed to natural conditions for a long time, and some northern regions use it De-icing salt is anti-slip and the service environment is rela...

AI Technical Summary

Problems solved by technology

On the one hand, because it directly bears the repeated rolling impact of the wheel, the concrete in the transition zone has high rigidity and poor deformation capacity, and cannot effectively absorb and transmit the impact energy of the expansion body; on the other hand, it has been exposed to natural conditions for a long time, and some northern regions use it Deicing salt is anti-slip, and the service environment is relatively harsh, making the expansion joint device the most vulnerable and difficult to repair part of the bridge structure, and its service life is far lower than the design life of the bridge

Frequent maintenance or replacement of expansion joints not only seriously affects the smoothness and safety of traffic, but also brings waste of resources and environmental problems, increasing the maintenance cost of bridges

[0003] At present, the concrete used in the transition zone of expansion joints is mainly ordinary concrete, steel fiber high-strength concrete and various resin concretes. However, these three concrete materials have the following problems: 1) Ordinary concrete is a typical brittle material with high compressive strength, but The low tensile strength, shear strength and impact resistance make the expansion joint structure difficult to withstand the repeated impact of long-term vehicles; 2) The tensile strength, impact resistance and fatigue resistance of steel fiber high-strength concrete are significantly improved compared with ordinary concrete The main disadvantages are that the amount of steel fiber high-strength concrete cementitious material is high, and the water gel is relatively low, which is prone to shrinkage and cracking. The poor interface bonding force between the reinforcement and the section steel is easy to form water seepage gaps; when the stress is applied, the bonding interface is easy to crack, thereby greatly reducing the durability and safety of the expansion joint structure; 3) Epoxy resin concrete has high strength, wear resistance Good resistance, good impact resistance, excellent bonding performance and chemical corrosion resistance, etc., but the main disadvantages are that the cured epoxy concrete is brittle, and the tensile deformation capacity is insufficient. In addition, epoxy resin is an organic material, and the problem of ultraviolet aging It is more serious, and the on-site preparation is more cumbersome, and the material cost and construction cost are higher

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