Interfacial properties and nanostructural characteristics of epoxy resin in cement matrix. (10th March 2018)

• Record Type: Journal Article
• Authors: Du, Jiapei; Bu, Yuhuan; Shen, Zhonghou
• Is Part Of: Construction & building materials. Volume 164(2018)
• Page Start: 103
• Page End: 112
• Publication Date: 2018-03-10
• Subjects: Cement -- Epoxy resin -- Molecular simulation -- CSH/resin interface -- Adhesion energy; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2017.12.200
• Languages: English
• ISSNs: 0950-0618

Abstract

Graphical abstract: Highlights: Experimental analyses and molecular simulations were used in this study. Ca 2+ ions make an electrostatic bond with hydroxyl function of resins. The attractive force between CSH and resin lead to an increase in Young's modulus. Electrostatic interaction is the main resource of adhesion energy. Abstract: Concrete is the most utilized material all over the world. However, a vital drawback of concrete is its weak tensile properties. Thus, since 1920, many researches were focused on enhancing the tensile properties of concrete by doping resin. However, a comprehensive understanding of the mechanical performance of resin-reinforced concrete demands knowledge of resin/cement interfaces in nanoscale. In this investigation, a combination of experimental analyses and molecular simulations has been utilized to study the resin/cement interface. A novel model of calcium silicate hydrate (CSH)/resin interface was modeled according to SEM and EDX analyses. The adhesion energy of resin/CSH interface was studied at nanoscale level since adhesion energy plays an important part in the design of resin-reinforced cement composites. The relationship between Young's modulus and adhesion energy was further studied. The results show that the polarity of resin enhances the attraction of positive ions and water molecules, such as Ca 2+ during hydration, to the resin molecules. The Ca 2+ ions from CSH gel migrate to the interface area and make an electrostatic bond with the hydroxyl function of the resins, which is the origin of adhesion energy. Thus, the more realistic adhesion energy or even Young's modulus for resin-reinforced cement can be estimated by the actual Ca/Si ratio in CSH gel. The results are important in the further development of resin-reinforced hybrid cement composites.