Effects of different modifiers on thermal stability, constituents and microstructures of asphalt-based sealant
- PDF / 1,175,037 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 79 Downloads / 219 Views
Effects of different modifiers on thermal stability, constituents and microstructures of asphalt‑based sealant Hanshuai Zhang1 · Xiaohui Sheng1 · Siwen Wang1 · Tao Xu1 Received: 15 May 2019 / Accepted: 15 January 2020 © Akadémiai Kiadó, Budapest, Hungary 2020
Abstract To develop a new sealant for the expansion joint on concrete pavement, styrene–butadiene–styrene (SBS), polyurethane (PU) and organ silicon (OS) were selected to modify asphalt, respectively, and effects of the three modifiers on thermal stability, main constituents, microstructures and chemical elements of asphalt, and their modification mechanisms were discussed. Results indicate that PU shows the most satisfactory modification effects on thermal stability of asphalt, followed successively by OS and SBS modifiers. Further, the aggregation state change temperatures of SBS- and OS-modified asphalt samples are not obviously altered, but SBS and OS play the comprehensive balance roles in lowering endothermic amount of asphalt. However, some components of asphalt react with PU to reduce the transition of aggregation state, leading to the decrease in endothermic reactions in PU-modified asphalt. Additionally, SBS, PU and OS are dispersed with asphalt matrix, but PU shows the most satisfactory dispersity in asphalt, followed successively by OS and SBS modifiers. Finally, three modifiers form network microstructures to improve mechanical strength and flexibility of asphalt. PU presents a better dispersity in asphalt matrix than other two modifiers. Physical modification is the main mechanism of three modifiers. PU is proposed to use as a modifier for preparing asphalt-based sealing material of expansion joint on concrete pavement. Keywords Pavement sealant · Expansion joint · Asphalt modifier · Thermal stability · Chemical element · Modification mechanism
Introduction Highway has been developed rapidly during the past decades in China [1]. Cement concrete pavement is one of the important paving structures. Expansion joints are designed on cement concrete pavement [2]. However, joints are weak links of cement concrete pavement system. Expansion joint failure is one of the important causes to result in distresses of cement concrete pavement [3]. A suitable sealant should be selected to seal expansion joints, which is beneficial to maintain the integrity, smoothness and water tightness of pavement slab. In addition, to reduce failures of sealing materials, sealing materials should have such favorable performances as high elongation, low modulus and strong adhesive property [4]. Studies on sealant were paid more and more attentions. * Tao Xu [email protected] 1
College of Civil Engineering, Nanjing Forestry University, 159 Longpan Road, Nanjing 210037, Jiangsu, China
Asphalt-, polymer-, silicone- and rubber-based sealing materials have been developed to seal expansion joints of cement concrete pavement. Li et al. [5] reported a new adhesive strength test method to determine the adhesive strength of self-leveling and non-self-leveling silicone sealants and p
Data Loading...
