Contribution on the Use of Household Waste as Bio-Admixture

In the civil engineering field, the incorporation of chemical admixtures is now a practical technics' used for improving the properties of concrete, such as improved workability, decreasing the water demand, increasing strength, etc. However, chemical admixtures have some disadvantages such as environmental pollution during both their manufacture and their use, else, there are rare somewhere. Because of this background, bio-admixtures appear principally useful, due to their environmental effect and friendly properties, bio-admixtures are substances obtained from a biodegradable product also resulting from the methanisation. The objective of this research is the valorization of household waste used as a bio-admixture. Moreover studying its effect on cement path workability, start/end of the cement setting.

Effect of the Treatments of the Surface on Mechanical Performance of Concrete Containing Chemical Admixtures

The aim of this paper is to investigate two different concrete mixes, one with Limestone Powder (LSP) and the other with Ground Granulated Blast-Furnace Slag (GGBS), both mixes containing superplasticizer, in order to analyse their compressive strengths at 7 and 28 days, their abrasion resistance and slip resistance. The two mixes are treated with two different surface protection finishers, applied on the surface after the concrete has cured and analysis of how these finishers affect the abrasion resistance and slip resistance of the concrete is discussed.

Effectiveness of Thermal Stimulation of Superplasticizers on Fresh Properties of Cement Mortar

Polycarboxylic acid-based superplasticizers are used in various types of concrete work. Wide variations in environmental temperatures are known to affect how well chemical admixtures perform as superplasticizers, influencing the properties of the concrete. However, little has been reported on changes in performance caused by thermal variations. Previous studies have reported that heating superplasticizers change the polymer structure, improving and sustaining cement particles' dispersibility. Moreover, the improved fluidity from thermal stimulation is not temporary. The effect has been observed to remain for about seven days, with the residual characteristics differing depending on the superplasticizers used. Therefore this study evaluates mortar stiffness when using thermally stimulated superplasticizers and evaluates how the stimulation affects construction performance using measures such as the flow and rheological properties (plastic viscosity) of fresh mortar, vane shear tests, blade viscometer tests, and mortar vibration box tests. Mortar's fluidity was found to improve by about 25% when using thermally stimulated additives, with plastic viscosity dropping by up to 45% and the stress likely to be needed for pumping also being reduced by about 16%. Filling speed was also found to increase by about 26%. Thus, thermal stimulation improves mortar and concrete construction performance, and it may be possible in the future to carry out the construction with fewer workers utilizing this technology’s benefits. The study indicates a need for further investigation of how thermal stimulation affects polymer molecules’ adsorption efficiency with cement to elucidate the mechanism at full scale and propose ways to adopt thermal stimulation at actual construction sites.

Development of Ultra Strength Concrete

Most superior cements delivered today contain materials notwithstanding Portland cement to help accomplish the compressive strength or solidness execution. These materials include fly ash, silica fume and ground-granulated blast furnace slag used discretely or in coalescence. Concurrently, chemical admixtures such as high-range di-hydrogen monoxide-reducers are needed to ascertain that the concrete is facile to convey, place and culminate. For high-strength cements, a blend of mineral and compound admixtures is almost consistently fundamental to guarantee accomplishment of the necessary strength. The Primer investigations have been done on concrete, Fine aggregate and coarse aggregate. The Blend Extent for M200 grade concrete is determined 1: 0.313: 1.463 by following the plan methodology given by ACI Strategy. By keeping up the w/c proportion as 0.25, the multi day Compressive strength, Flexural strength and Split elasticity of cement at 3% of silica fume and 1.5% of conplast have been accomplished as 163.33 N/mm2, 8.4 N/mm2& 9.5 N/mm2 separately. The variety of solidarity of cement with the variety of silica fume is appeared in bar outline. The strength of the concrete might be as yet expanded by decreasing the w/c proportion and expanding the level of silica fume

Durability and Self-Sealing Examination of Concretes Modified with Crystalline Waterproofing Admixtures

Repairing concrete structures costs billions of dollars every year all around the globe. For overcoming durability concerns and creating enduring economical structures, chemical admixtures, as a unique solution, have recently attracted a lot of interest. As permeability of a concrete structure is considered to play a significant role in its durability, Permeability Reducing Admixtures (PRA) is one of the ideal solutions for protecting structures exposed to water and waterborne chemicals. Different products have been developed to protect concrete structures against water penetration, which, based on their chemistry, performance, and functionality, have been categorized into PRA. As it has previously been tested by authors and proven to be a promising solution, a hydrophilic Crystalline Waterproofing Admixtures (CWA) has been considered for this study. This paper aims to investigate how this product affects concrete’s overall freeze–thaw resistance, self-sealing, and corrosion resistance. Various testing methods have been utilized to examine the performance of CWA mixtures, including the linear polarization resistance, resonance frequency testing, half-cell potential, and self-sealing test. The reinforcement corrosion potential and rate measurements indicated superior performance for CWA-treated samples. After being exposed to 300 freeze–thaw cycles, concrete mixes containing CWA—even non-air-entrained ones—showed a Durability Factor (DF) of more than 80% with no signs of failure, while non-air-entrained control samples indicated the lowest DF (below 60%) but the greatest mass loss. The major causes are a reduction in solution permeability and lack of water availability in the concrete matrix—due to the presence of CWA crystals. Furthermore, evidence from the self-sealing test suggests that CWA-treated specimens can seal wider cracks and at a faster rate.

Investigation of Mechanical and Durability Properties of Concrete Mixed with Water Exposed to a Magnetic Field

Water is a crucial element in the concrete mix and is alone responsible for concrete work ability and cement hydration. The massive quantity of potable water consumed during the production of concrete is a concern. In general, fresh and hard concrete qualities are most influenced by the quantity and water quality. The use of magnetic water in concrete gives many benefits when it comes to increasing its properties. A substantial quantity of water can be saved by substituting potable water with magnetized water in concrete. In this study, the effects of magnetized water on the concrete's mechanical and durability properties were tested. Four different combinations were made using potable water and magnetic water. Mechanical properties including compression, flexural, tensile strength, and SEM analysis were evaluated. Water absorption, acid resistance, and corrosion resistance were all tested as part of the durability tests. According to the results of the experiments, employing magnetic water for concrete preparation and curing enhanced the mechanical properties and durability. Concrete mix MMMC prepared and subjected to curing using magnetized water has a 14.86% greater compressive strength than ordinary concrete. Similarly, tensile and flexural strength of mix MMMC amplified to 14.32% and 14.02%, respectively. Besides, the consumption of chemical admixtures also considerably reduced in magnetized water imbibed concrete.

Durability Experiences on the Traditional and SCM Founded Blended Concrete

Concrete might be the maximum substantially used construction material in the global with approximately six billion tones being produced each year. It is best subsequent to water in phrases of in keeping with-capita consumption. However, environmental sustainability is at stake both in terms of damage due to the extraction of raw material and CO2 emission all through cement manufacture. This brought pressures on researchers for the discount of cement intake by means of partial substitute of cement by using supplementary materials. These materials may be obviously happening, industrial wastes or by way of-products that are less energy extensive. Fly ash and Ground Granulated Burnt Slag (GGBS) are selected specifically based totally on the standards of fee and their long lasting qualities., Not best this, Environmental pollution also can be decreased to a point due to the fact the emission of dangerous gases like carbon monoxide & carbon dioxide are very restricted. These substances (referred to as pozzalonas) when combined with calcium hydroxide, reveals cementitious compositions. Most commonly used pozzalonas are fly ash, silica fume, met kaolin, ground granulated blast furnace slag (GGBS). This wishes to look at the admixtures performance whilst combined with concrete so as to ensure a discounted existence cycle fee. The present research consists of three phases and reports the specializes in investigating characteristics of M35grade concrete .In the 1st phase the behavior of standard and SCM concrete (7.5%FA and 7.5%GGBS) of M35 grade specimens with different percentages of chemical admixtures curing with acids such as HCL. 2nd phase the same grade of specimens curing with Alkaline such as NaOH and in the 3rd phase the same grade of specimens curing with sulphate solution MgSO4 and finally assess the losses of mechanical properties and durability considerations of the concrete due to these conditions were reported.