Construction Technology Of Sfrpc Bridge Deck Pavement

It is reported that 32% of bridges in service are structurally or functionally deficient in present. The deficiencies are usually due to aggressive agents penetrating into the concrete deck. In recent years, deck pavements of some highway bridges are needed to repair soon after opening to traffic. These problems are of great concern to the government and the public. They also become hot issues to departments of design construction and administration.Unlike the pavement overlays, bridge deck overlays typically have no structural purpose. They are primarily used to improve the durability and to extend the service life of the bridges deck. Bridge deck overlays are most designed based on previous empirical knowledge. One of the main factors affecting the durability and service life of a bridge deck is the speed by which aggressive agents penetrate into the concrete deck. In addition to porosity, concrete permeability is dominated by the presence of cracks. Hence, the main goal in bridge deck pavement design is to control and minimize cracking. A well-designed bridge deck overlay system should meet the following requirements: (1) high early and long-term strength; (2) very low permeability; (3) high resistance to debonding or delamination; and (4) maintenance-free service for over 10 year. The main factors in overlay design are (1) material type; (2) overlay thickness; and (3) bonding between the overlay and the bridge deck, which are related to the technology in construction. This paper is concerned with the above three problems for the cement concrete bridge deck pavement.1. Development of steel fiber reinforced polymer concrete(SFRPC) pavement materialSteel fiber reinforced polymer concrete(SFRPC), can overcome the shortages in the polymer-modified concrete and steel fiber concrete, but keep their merits. So, SFRPC has high strength, high impact resistance, high ductility, high crack control, high durability, low permeability and relatively easy construction. Thus, it is ideally suitable for being bridge deck pavement material.2. Theory and DesignBased on experiment of research, the numerical and elastic analysis, this thesis takes into account of the demands of the cement concrete bridge deck pavement, simplifies the loads applied on the pavement and then makes some assumptions according to the realistic conditions. The author then puts forward a design method, which is based on the maximal bending moment of bridge, and takes the crack and fracture of cement concrete bridge deck pavement as a control index.