Effects of Calcium Carbonate Nanoparticles and Fly Ash on Mechanical and Permeability Properties of Concrete

Abstract

The use of additives to supplement or replace cement in concrete is a well-studied topic. The use of fibers, polymers, minerals, and even nanomaterials has been considered for improving concrete properties such as permeability and strength, and these issues are constantly under investigation. In this study, the mechanical properties and permeability of concrete containing calcium carbonate (CaCO3) nanoparticles and fly ash are investigated. For this purpose, concrete specimens with different proportions of nanoparticles and fly ash were prepared and aged for 7 days and 28 days to investigate the mechanical properties via compressive strength tests, tensile strength tests, and flexural strength tests under three-point loading and also to study the permeability properties via full water absorption tests and the testing of penetration depth under water pressure. To determine the distribution of nanoparticles and their size and microstructure, scanning electron microscopy (SEM) images were obtained, and energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) analyses were performed. The results show the positive effect of CaCO3 nanoparticles in filling concrete pores, which leads to increased strength and reduced permeability. In general, the SEM images and EDS and XRD analyses showed that there was a good correlation between the materials used in the concrete and also that the nanoparticles were appropriately distributed in the concrete samples.

Mechanical properties and microstructure of hybrid vulcanized natural rubber filled with carbon black and nano-CaCO₃ from <i>Achatina achatina</i> Shells

“…The compression sets obtained in the composites are also in agreement with earlier report [9]. Similarly, calcium carbonate nanoparticles have been reported to increase the compressive strength of concrete [21].…”

Effect of Nano-Materials on Autogenous Shrinkage Properties of Cement Based Materials

“…As the NC content increases, the probability of NC particles' agglomeration raises. It leads to nonuniform dispersion of NC in the matrix, increasing the air void content in cement paste, which weakens inhibitory effect of NC on the autogenous shrinkage of cement paste [27]. Table 6 shows the final shrinkage strain values of cement based materials with different nanomaterials.…”

Concrete Performance Attenuation of Mix Nano-SiO2 and Nano-CaCO3 under High Temperature: A Comprehensive Review

“…Some authors suggested that the hydration effect of NS is concentrated at 7D and 28D, and that the later effect is not significant, mainly due to the volcanic ash effect and hydration reaction of the material [ 80 , 81 ]. On the contrary, some authors suggested that the role of NC is to enhance the mechanical properties after filling the microstructure, and its hydration effect is not strong [ 82 ], and the experimental effect of mixing NC and NS is more neutral. The authors of Z. hang Wang et al [ 49 ] showed that mixing NC and NSC significantly improved the dynamic and static mechanical properties of nano concrete while mixing NS alone weakened them.…”

“…The volcanic ash effect and microfilling effect of a certain amount of NC and NS replacement cement incorporated into the concrete results in a more dense concrete, reduced water absorption and hazardous material permeability, and improves freeze-thaw resistance. Authors Nejad et al [ 82 ] used fly ash composite-modified concrete at only 1% admixture, where nanomaterials and fly ash were used in combination, while authors H. Liu et al [ 87 ] used NC alone to increase the testing of hydrochloric acid resistance experiments to increase the admixture of NC modification to 3% in order to obtain a better durability performance response. It is advisable to use between 2.0% and 3.0% nano-doping for bulk concrete.…”