_applied sciences_  
_Article_  
**Property Analysis of Double-Sided Composite Waterproofing Sheet for Simultaneous Application on Asphalt Concrete and Late-Modified Concrete Pavements for Bridge Decks**  
**[PERSON] 1, [PERSON] 2, [PERSON] 2, [PERSON] 3, [PERSON] 3 and [PERSON] 3,4,*(c)**  
Footnote 21: [[https://www.mdpi.com](https://www.mdpi.com)]([https://www.mdpi.com](https://www.mdpi.com))A review of current bridge waterproofing designs and studies indicates that waterproofing methods to protect bridge decks are susceptible to change depending on the type of pavement technology [3; 4]. [PERSON] et al. provide a study on the tendencies of failure adhesion of commonly used asphalt layer waterproofing to the pavement overlay, and provide an outline on effective waterproofing methods and strategies [5]. [PERSON] published an extensive report on the various waterproofing material types and methods, but among them, new bridges sometime do not employ the usage of waterproofing layers [6]. [PERSON] et al. researched and modelled the adhesion performances of two different types of concrete pavement of bridge decks with asphalt overlay, and outline the necessary parameters for accurate analysis [7]. [PERSON] discusses the possibility of using thin overlays that protect the pavement layer, a newly proposed technology that is intended to supplement the common adhesion problems between asphalt overlap and concrete [8]. In some cases, the presence or absence of a waterproofing layer is determined by the type of paving methods. Most bridge deck slabs (bridge pavement structures) are comprised of high strength and rigid concrete, and then asphalt concrete (APC, hereinafter referred to as APC) or latex-modified concrete (LMC, hereinafter referred to as LMC) is subsequently installed as a pavement layer (or material). In the case of APC pavement as a bridge waterproofing method, chloroprene-rubber-based coating or modified asphalt sheet has been conventionally used for a long time [5; 6]. This is because when APC is mixed in high-temperature conditions (temperature can increase up to 180 \({}^{\circ}\)C) [7] with asphalt and aggregate (gravel) as pavement materials, the chloroprene rubber or modified asphalt sheet adheres well to APC and can withstand the high temperature and rolling pressure of APC. Chloroprene rubber coating or modified asphalt sheets have produced successful results with waterproofing to protect the leakage of bridge decks with continuous performance maintenance in Korea [7], but it recent discoveries indicated that chloroprene rubber coating is a cause of air pollution [8; 9], modified asphalt sheets are mainly used instead in the Korean market [10; 11]. Modified asphalt sheets, in comparison to asphalt overlays, have higher adhesion performance, but are susceptible to wear and damage due to shear force, which could potentially lead to adhesion failure. LMC pavement is also widely used as a bridge and road pavement material in addition to APC [12]. LMC is a paving material made by adding a latex-based polymer into concrete [13]. This is a technology that provides elasticity and watertightness to concrete to reduce cracking, and waterproofing performance to the concrete itself and is often considered to not require a waterproofing layer on the bridge deck surface [14]. Traditionally, concrete pavements are subject to a higher rate of thermal expansion and deflection, as they are directly exposed to wheel load and thermal variation from environmental sources. Concrete pavements are, therefore, known to be susceptible to cracks, freeze-thaw damage, etc., occurring in the pavement layer and lose waterproofing performance (Refer to Figure 2 for cases of deterioration in bridges). Despite their design to be inherently watertight, the problem of leakage of the bridge deck surface persists in concrete-based pavements, including LMC [15]. In this regard, in the case of LMC pavement, the necessity of providing  
Figure 1: Types of water-leakage on bridge deck; (**a**) joint leakage, (**b**) slab leakage.