Research On Waterproofing Performance Of Asphalt Concrete Bridge Deck Pavement

Setting reasonable waterproofing system and using the good performance of waterproof material can effectively reduce or prevent an appearance of early-stage destruction on asphalt concrete bridge deck pavement, which is one of the most effective measures to improve the bridge durability, and also is the criticle technology to cope with the design and construction of bridge at present.The early destruction of asphalt concrete bridge deck pavement is systemic analysed in the paper. The results show that many factors effect the early destruction such as: waterproof layer, the constraint condition of bridge pavement, thickness of deck pavement, overload and unbanlance load, construction technology and quality, drainage design and cement concrete surface condition and so on. Under repeated moving vehicle, the water infiltrated in deck is the main factor which cause the destruction of bridge pavement. So, the design of the waterproofing and drainage system of bridge deck should be perfected, while the overload situation on the design of bridge deck pavement should be strictly control.The paper analyses the using condition and performance of the waterproof layer, introduces the classification and main performance of the waterproof material, which provides the basis for chosing the waterproof material reasonablely. According to the performance index of waterproof material and combined with the factors such as bridge situation, local climate condition, material characteristics, three kinds of waterproof materials were chosed to test their performances.Based on the Darcy theory with variable head testing methods by using SL-4 permeability instrument, this paper systematically studies the permeability of bridge deck paving composite structure, and also evaluates the permeability of the different waterproof coating under the conditions of the convertion, salt corrosion and thawing environment, which can provide scientific basis for the waterproof design of asphalt concrete bridge deck pavement.Then,the MTS810 material testing machine was used to do the experiment of shearing and pulling tests in the paper, the interlayer stability of pavement structure was studied, and the per unit area optimum content range of different waterproof coating and the variation of shear strength with shear rate and temperature was determined, also the relationship between shear strength and bond strength was established in the paper.Finally, based on the economic benefit and the social benefit analysis on the different waterproof coating, and combed with the experiment results of laboratory and field test, the good comprehensive properties of waterproof coating for the real project was recommended in the paper. Meanwhile, the construction technology and the methods of quality detection and acceptance check were presented for flexible waterproof layer.