Abstract
In this work, a method of imparting hydrophobicity and high strength to hardened cement paste (HCP) is proposed. Sodium laurate (SL) was used as a hydrophobic modifier and nano silica (NS) as a pozzolan. The HCP was modified by SL and NS simultaneously. HCP modified with different contents of SL and NS was prepared. Surface wettability, micro-structures, chemical composition, and organic structure were systematically studied using contact angle (CA) measurement, scanning electron microscope (SEM) observation, X-ray photoelectron spectroscopy (XPS), and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), respectively. The surface CA of the sample is 138.5° and has high hydrophobicity. Compared with the reference sample, the water absorption of the modified sample reduced by 96.55%, while the compressive strength only reduced by 6.91%. Therefore, using hydrophobic modifier and reinforcing agent as cement admixture is an effective method to endow concrete with hydrophobicity and high strength at the same time.
Highlights
Most of the corrosion effects on concrete during service are related to water [1,2,3]
The results show that when the addition amount of calcium stearate (CaSt) is 4%, the water absorption of the sample can be significantly reduced
Sodium laurate is cheap and soluble in water at room temperature, so it is easy to mix with cement powder in water uniformly
Summary
Most of the corrosion effects on concrete during service are related to water [1,2,3]. The corrosion of concrete is essentially the corrosion of hardened cement paste (HCP). Silicate-based HCP is composed of hydrated calcium silicate (CSH), portlandite (CH), ettringite (AFt), unhydrated cement powder (C), and a large number of pores [2]. The surface of HCP contains a large number of hydroxyl groups and is hydrophilic. Water can penetrate HCP [4,5,6]. When concrete is in service, it is unavoidable to come into contact with water, rain, snow, and other water sources in rivers and lakes
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
