Preparation and Self-Healing Properties of Clinker/PVP Microsphere in Cement Paste.

Jun Li,Wenting Li,Zhengwu Jiang

doi:10.3390/ma13030589

Abstract

This paper presents a new insight into the autolytic mineral self-healing method for cementitious materials. The clinker/PVP (polyvinyl pyrrolidone) autolytic microsphere was prepared via the film coating method with cement clinker as a healing agent and PVP as the autolytic coating film. The morphology and chemical structure of the microsphere were characterized by environmental scanning electron microscopy (FESEM) equipped with energy dispersive spectrometer (EDS) and Fourier transform infrared spectroscopy (FTIR), respectively. The clinker retaining original mineral healing composition was successfully coated with a PVP film confirmed by FTIR. The maximum film thickness was 7.54 μm, which was determined by laser particle size measurement. The autolytic behavior was measured using isothermal calorimetry and successfully controlled by pretreatment degree (i.e., silane coupling agent amount). Experimental results showed that the compressive strength recovery of cement paste with a 30% microsphere was 54% higher than ordinary cement paste specimens. The damage degree of the specimen was also decreased by adding the autolytic microsphere.

Highlights

Concrete is the most widely used material in modern construction since Portland cement was developed in the 1820s
The prepared autolytic microsphere was mixed into the cement paste and the backscattering specimen was prepared after preliminary hardening
The results prove that the protective effect of polyvinyl pyrrolidone (PVP) protection film can be achieved

Summary

Introduction

Concrete is the most widely used material in modern construction since Portland cement was developed in the 1820s. Man-made repair is a conventional solution, problems ae often encountered in repair work resulting from not-visible or inaccessible cracks, or structures in complex environments [5,6,7]. It is high-cost and high-labor operation work which only lasts 10–15 years [8,9,10]; there are calls for a more sustainable approach [11,12,13]. The well-known autogenous self-healing is a natural phenomenon of cementitious materials [14]. The healing efficiency of autogenous healing is poor and difficult to control [4]

Methods

Results

Conclusion