Abstract： There are variety of surface treatments used for concrete structures protection . This paper presents a review of the effect of surface treatments on mechanical properties and durability concrete, and the durability of treatment materials themselves. Several common surface treatment are reviewed, including acrylic coating, polyurethane coating, epoxy coating, silanes, siloxanes sodium silicate, and nano-SiO 2 . These surface treatments showed different impacts on physical and mechanical properties, water permeability, chloride migration, carbonation resistance, sulphate attack, and freeze-thaw cycle. It is important to consider their strengths and weakness when choosing a surface treatment. In addition, there are limited prediction model for the service-life of treated concretes, though many tests were conducted to measure the barriers properties of these surface treatments. Many of the surface treatments, especially organic treatments, are generally subjected to aging and weathering, and thus the long-term protection cannot be promised. Hence, both the protective effect and long-term durability of the surface treatment should be taken into account in service-life modelling.In many cases, the reliability of concrete structures is, determined by durability problems, 24 e.g. carbonation, corrosion of steel bars and sulfate attacks [1, 2]. The surface layer of 25 concrete which usually refers to a 30 mm thick layer below the surface affords both physical 26 and chemical protections against ingress of aggressive substances [3][4][5]. Since many 27 aggressive substances transport through water or air, the permeation characteristics of the 28 surface concrete is an important factor for the durability of whole concrete element [5][6][7][8]. 29 Surface treatment is an economical and effective method to improve the quality of surface 30 layer and protect the concrete structure compared with other methods, such as decrease water 31 to cement ratio and add admixtures etc. 32 There are a variety of surface treatments that can be used for protection of concrete. 33 According to the chemical compositions of the surface treatment agents, the surface 34 treatments can be classified into two groups: inorganic and organic [9][10][11]. The organic 35 surface treatments have good barrier properties, but their limiting service life has got wide 36 concerns. The inorganic surface treatments are more stable and have better resistance to aging, 37 but limited studies about their application have been published. Surface treatments were 38 grouped into four categories according to functions. (a) Surface coating can form a continuous 39 polymer film and create a physical barrier to suppress the ingress of the aggressive substances 40 [12][13][14]. Many surface coatings have been using in foundations and quays, e.g. acrylic, 41 butadiene copolymer, chlorinated rubber, epoxy resin, oleoresinous, polyester resin, 42 polyethylene copolymer, polyurethane, vinyl, coal tar and polymer modified mortar [15]. (b) 43 ...
