ABSTRACT
Research trends in the construction industry is toward the application of nano materials in mortar/concrete which could act as set accelerator due to the ultrafine nature of silica nano_particles (SNPs). The study is aimed at investigating the effect of SNPs on the performance of Sorghum Husk Ash (SHA) and Calcium Carbide Waste (CCW) binder based mortar with a view to establishing its suitability. SHA was an incinerated ash from agro-by-product of sorghum husk with major component of amorphous silica (SiO2) when combined with calcium carbide waste (CCW) an industrial by-product from an acetylene gas production process with major component of lime (CaO) in the presence of water to forms compounds possessing cementitious properties. Assessment of mortar in fresh state, early-age strength development and hardened properties were carried out. Pastes from different binder 70/30 (SHA_CCW) containing 0.5% to 5% at 0.5 step interval of SNPs. The water-to-binder ratio (w/b) and High Range Water Reducer Admixture (HRWRA) was optimized at 0.5 and 1.5% respectively by mass of binder. With a normal mix of 1:3 binder/sand, samples were studied for flowbility, air content, setting times, degree of hydration, water absorption, abrasion resistance and compressive strength was also determined at ages (3, 7, 14, 28, 56 and 90 days). Mortar samples with 3.0% (SNPs), exhibited better performance at 28 days with compressive strength value of 7.45 N/mm2 representing 137% of 70/30 (SHA_CCW) strength and 90 days with compressive strength value of 9.01 N/mm2 representing 134% of 70/30 (SHA_CCW) strength. SNPs (3.0%) and SHA_CCW (70/30) in 1:3 binder/sand mortar at 0.5 w/b with 1.5% water-reducing admixture is recommended for use in masonry work as it conforms to class N mortar of ASTM C270.
CHAPTER ONE
1.0 INTRODUCTION
1.1 Background of the Study
Nano-technology according to Khasn (2011) and Birgisson et al. (2010), was interpreted as the science of altering, monitoring the exhibition, performance of materials at the nanoscale Khan (2011) went on to describe nanoscale materials as a set of parts, all of which are interconnected whereby one point is actually less than 100 nanometers. A nanometer is one millionth of a millimeter – nearly 100,000 times tinier than the width of the hair of a human. Bakhoum et al. (2017), concurred that it is the process of making an appliance or material with key components at the atomic and molecular scale.
Bakhoum et al. (2017) went on to say that nanotechnology is a current promising area in terms of enhancing environmental improvement such as energy conservation and non- renewable resource management, as well as reducing waste, hazardous substances, and carbon emissions. Ganesh (2012) stated that nanotechnology would contribute to the creation of objects with specific features, which could provide interesting answers for achieving sustainable housing project and introducing innovations for cost-effective spaces inside a facility. Nanotechnology is a branch of research and innovation that focuses on both knowing and managing issues at the subatomic level and as a result, affecting the material’s properties (Grove, 2010 and Vishwakarma et al., 2016).
According to Abbas (2011), Jonbi (2013), and Khanzadi (2010), nano silica (NS) has a great pozzolanic reactivity, which has important implications for the behaviour of cement-based matrix composites in both the freshly and set states. Sadrmomtazi (2012) and Abbas (2011) pointed out that NS reduces set times, increases hydration temperature escape, and alters the rheological characteristics of solid pastes and mortars in the fresh form. Sadrmomtazi (2012), Abbas (2011), and Jonbi (2013) have
demonstrated that NS improves crushing performance, reduces porosity, and improves a few aspects of resilience in the hardened state. SNPs have been discovered to cause significant mineralogical changes, especially in C-S-H and portlandite, according to a few studies (CH). In terms of C-S-H, NS floods the movement, the models blended with NS have a greater C-S-H material, and it provides a strategy of lasting C-S-H as compared to the control samples (Abbas, 2011; Jonbi, 2013 and Khanzadi, 2010). The need to use wastes from manufacturing or unindustrialized processes in the construction industry stems from the need to include construction constituents that can be maintained (Hardjito et al., 2012). According to Olumuyiwa et al. (2018) and Sunusi (2015), this can be accomplished by looking for and incorporating new eco-friendly resources and products, as well as leading to a reduction in carbon dioxide emissions into the atmosphere.
Sorghum belongs to the family of cereal crop also known as grain sorghum which has a place with the general name of sorghum, (Chukwu, et.al., 2011 and Ndububa et al., 2015). Tahomah et al. (2017) revealed that it is one of the most well-known seed grain delivered in Africa. Sorghum/sorghum grain is for the most part developed in the northern region of Nigeria in states like Kaduna, Bauchi and Plateau. When collected, it is ordinarily handled precisely by the utilization of consolidated reapers or physically by sifting with sticks leaving a huge amount of buildup (husk) establishing ecological waste yearly.
The benefits of using agro waste to replace cement will lower cost per ton as compared to Portland Cement (PC), reduced waste management, waste movement control at a low cost, and improved economy base/gross domestic product of local farmers when such waste is exchanged, enabling more production conservation of limestone deposits (Ndububa et al., 2015; Mahmoud et al., 2012 and Manasseh., 2010).
The examination of the Sorghum Husk Ash (SHA) indicated that a blend of its substance constituents qualified it as a pozzollana (ASTM C618-92a). Pozzolan as uncovered by Ndububa et al. (2015) and portrayed by ASTM (C618) are “siliceous, aluminous substance which in themselves have no/little cementitous properties yet in unbelievably confined structure and with water they can react with calcium hydroxide (CaO) which is dissipated during the hydration of PC at room temperarure to form blends having cementitous characteristics”. Calcium_Carbide_Waste (CCW) is a waste material produced using oxy-acetylene gas utilized in welding works (Chukwudebelu et al., 2013). CCW is abundant in our condition and explores have been composed to pick its use as an assistant structure progression material. Calcium Carbide Waste (CCW) as uncovered by Makaratat et al. (2011) is side-effect gotten from the acetylene-gas (C2H2) produce process as appeared in Equation (1.1). CaC2 + 2H2O→C2H2 + Ca (OH)2
Research discoveries by Makaratat et al. (2011); Olumuyiwa et al. (2018) have indicated that CCW, when gotten together with certain pozzolan, for instance, FlyAsh (FA), Silica Fume (SF), containing high silicon dioxide (SiO2) and aluminum oxide (Al2O3) could yield last things that resemble those acquired from Portland Cement (PC) hydration process. More looks at are up ’til now being coordinated on usage of CCW being developed. Sun (2015), further observed that CCW contains some blend sythesis.
1.2 Statement of the Research Problem
The inclusion of wastes from industrial or Agro processes in the construction industry according to Hardjito et al. (2012) and Abdurra’uf et al. (2017) is accepted out of the necessity to provide sustainable materials for building. This is achieved either by incorporating existing or incorporating new materials and waste products that are more eco-accommodating as well as contributing towards the lessening of carbon dioxide (CO2) discharged into the atmosphere. Previous study on the use of sorghum husk ash (SHA) and calcium carbide waste (CCW) for the production of pozzalanic binder was found to exhibit positive hydration characteristics. Notwithstanding, the SHA-CCW combination was reported to exhibit slow hydration process with an accompanying lower strength characteristic, particularly at early age (Egwuda, 2017). This study is an attempt to improve on the early and latter properties of SHA-CCW binder as continuation of previous attempt at development of an alternative binder by Egwuda (2017). It is in this attempt that this current research focused on the use of silica nano particles (SNP) with a view to improving the strength development characteristics of the developed binder.
1.3 Aim and Objectives
This thesis is aimed at assessing the pozzolanic behaviour of SNPs and the impact it has on the mechanical, transport properties of SHA and CCW based mortar with the end goal of establishing its sustainability.
The objectives are to:
1. Determine the physio-chemical properties of the SHA, CCW and SNPs.
2. Determine reasonable quantity of the SNPs as constituent material and its impact on the early properties of SHA_CCW based mortar.
3. Examine the preparation and characterization of SHA for the manufacture of nano-silica.
4. Examine the mechanical and long-term toughness of mortars made with SNPs as an admixture in the SHA CCW binder.
1.4 Scope of Work
This exploration was aimed at examining the usage of the SHA and CCW as whole substitution of cement in mortar products and choosing the physio-engineered characteristics of the fundamental materials, examining the physical properties tests, for instance, (sieve analysis, specific-gravity, moisture content, and bulk density), and the mixture structure of the important components. Regardless of how previous SHA and CCW examinations have been performed as a distinct experiment in Egwuda (2017), there is an evaluation gap in the study of blending mixed SNPs in SHA and CCW on the properties of mortar. This evaluation will look at the new properties of mortar made with SNPs as an admixture in a 70/30 SHA CCW ratio, for example.
1.5 Need of the Study
For several years, the high cost of cement is a major impediment to stable and long- term accommodation. Nigeria’s government however announced the launch of a mortgage refinance scheme that would offer 10,000 dwellings to the country’s people (Andrews, 2014). One answer to the housing affordability and sustainability crisis, according to Ndububa et al. (2015), is to substitute a portion of cement in concrete and mortar with economical and possible pozzolanic assets from agro and mechanical litters.
Additionally, in land filling using waste materials produced from most industries, for example, marble, stone, flexible, plastic, ended, material, calcium carbide and so on; as indicated by Bakhoum et al., (2017) is inciting waste ejection issues. Such sorts of litters as detailed by Vishwakarma et al., (2016) have pozzolanic activity which are progressively utilized in the improvement business for concrete so as to diminish the Co2 spread from the industrial activities.
Regardless Bakhoum et al. (2017) concurred that during the modification of structures, Engineered Nano-Materials (ENMs) contained in past developed facility are reused or become improvement fillers. Nattapong et al. (2010). Reviewed the impacts of Calcium Carbide ResidueFly-Ash (CCR-FA) binder on mechanical performance of concrete and saw that the solidified cement passed on from CCR-FA blends had mechanical properties like those from typical PC concrete.
A few researches had been made of late to profit the utilization of nano- applications and sciences in the field of cement binder-based materials age as a substitute for cement or fine sand with varying degrees. By a wide edge a massive bit of this evaluation depended in the wake of utilizing improvised materials (for example Silica particles) in a nano-scale to strengthen the properties of concrete based materials unequivocally concrete and mortar, (Bakhoum et al., (2017).This investigation investigate the fruitful regions of utilizing SNPs in improving the performance and qualities of cement-based materials and upgrading the idea of practical development, from this time forward, the imperative to check for the impact of quantity of SNPs as set quickening agent in SHA_CCW fastener.
This material content is developed to serve as a GUIDE for students to conduct academic research
EFFECT OF SILICA NANOPARTICLES ON THE PERFORMANCE OF SORGHUM HUSK ASH AND CALCIUM CARBIDE WASTE BINDER BASED MORTAR
Project 4Topics Support Team Are Always (24/7) Online To Help You With Your Project
Chat Us on WhatsApp » 09132600555
DO YOU NEED CLARIFICATION? CALL OUR HELP DESK:
09132600555 (Country Code: +234)
YOU CAN REACH OUR SUPPORT TEAM VIA MAIL: [email protected]
09132600555 (Country Code: +234)