Enhancement of the Concrete Durability with Hybrid Nano Materials

Heba A Gamal,Aref A Abadel,Mohamed Kohail,Yousef R Alharbi,M S El-Feky

doi:10.3390/su13031373

Heba A Gamal, Aref A Abadel + Show 3 more

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https://doi.org/10.3390/su13031373

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Abstract

The importance of the incorporation of nanomaterials in concrete has emerged as a promising research interest due to the outstanding functionalized properties of the materials at that size level. This study aims to investigate the engineering and durability properties of concrete incorporated with hybrid nanomaterials. In this study, the influence of carbon nanotube (CNT) on microstructure, mechanical, and corrosion characteristics of nano-clay-based (NC) concrete has been evaluated. The cement was replaced with CNT at different percentages of 0.01%, 0.02%, and 0.04% by weight, while NC was replaced at a constant percentage of 5%. A scanning electron microscope (SEM) was used to examine the microstructural characterization of the samples. To investigate the influence of carbon nanotubes in the fresh properties, slump and air content tests were carried out. The compressive strength, tensile strength, flexural strength, and bond strength of the hardened concrete was evaluated according to ASTM standards. The porosity of specimens was determined by carrying out the sorptivity and water penetration tests. The corrosion resistance of the steel bar embedded in concrete was assessed. The results of SEM examinations showed that incorporating CNT into the nano-clay-based concrete remarkably achieved a denser structure at all studied contents. Further, significant enhancements in the mechanical properties, durability, and chloride penetration resistance were attained when incorporating CNT in the NC concrete. Further, adding CNTs improves the corrosion resistance and has proven useful resistance to crack propagation within the concrete matrix as compared to the control mix without CNT. Results of this study prove that the incorporation of hybrid nano CNT and NC gives better performance for mechanical strength and durability properties.

Highlights

Concrete has been vastly used in the construction field because of its high compressive strength, low cost, as well as availability of its raw materials
In the fresh stage, adding carbon nanotube (CNT)% in the cementitious composites increased theofair compared to the control sample
Of more CNT caused a decrement in the slump of concrete

Summary

Introduction

Concrete has been vastly used in the construction field because of its high compressive strength, low cost, as well as availability of its raw materials. Its poor resistance to tension stresses makes it quasi-brittle, susceptible to cracking, and undergoes fracture rapidly when the tensile loads are applied. The reinforcing components such as steel bars solve this problem, behaving as a skeleton of the whole structure, and is capable of holding aggregates under tensile loading. After passing 28 days of the curing period, the cementitious paste provides and protects the steel rebar with an alkaline environment by creating a protective ferric oxide film in the high pH environment of concrete. Concrete could help in the protection of reinforced steel when being of high pH level, the level that is developed by the cementitious hydrated products especially by the addition of cementitious based supplementary cementitious

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