Use Of Laterite Research Articles

EFFECTS OF LATERITE ON STRENGTH AND DURABILITY OF REINFORCED CONCRETE AS PARTIAL REPLACEMENT OF FINE AGGREGATE

Throughout the world, concrete is widely utilized in buildings, and due to a rise in construction activity, there is a growing requirement for fine aggregate. This study aims to examine how laterite, which replaces some fine aggregate in reinforced concrete, affects the material’s strength and durability. The physical properties of materials were investigated. The compressive strength and flexural strength of laterized concrete were determined for each replacement level of 0, 10, 20, 30 and 40% at a mix ratio of 1:2:4 and a water-cement ratio of 0.65, while for the water absorption, the percentages replacement of laterite to fine aggregates was 0, 10, and 20 % with the same mix ratio and water cement ratio. A 100 X 100 X 100 mm cube and 100 X 100 X 350 mm beams were tested for compressive and flexural strength at 7, 14, 21 and 28 days of curing respectively. Water absorption was determined at 28, 56 and 90 days of curing age. The findings show that as the percentage of laterite substitution increases, the laterized concrete’s workability declines. However, the strength properties of the concrete partially replaced with laterite increase with curing age and decrease as the laterite content increases. Moreover, the water absorption of laterized concrete is increased by the inclusion of laterite. It was concluded that the use of laterite in the production of concrete should not be more than 10 %.

Performance Study of Laterised Concrete Made with GGBS and Silica Fume as a Partial Replacement of Cement

Abstract -Sand has been utilized in the construction of civil engineering projects for a long time as a fine aggregate. As building costs have been rising over the past few years, the source of high-quality sand has been rapidly depleting. Now, laterite is thought to be a potential sand substitute for concrete mixtures. In this Paper, GGBS and silica fume is used as a partial cement replacement in laterised Concrete. This research deals with the viability study of GGBS and silica fume as partial replacement of cement in laterised concrete. Mixes to be prepared with replacement content of 5%,10%,15%,20% and 25% by the weight of ordinary Portland cement with GGBS and optimum silica fume (10%). However, the addition increases the strength levels with the aid of super plasticizer. Additional mixing lowers the laterite content to 15%. Same 15% of the weight of laterite soil can be used as partial replacement of sand exhibited the finest outcomes. As a result, it is showing use of laterite as a possible partial replacement for sand. In this research mixes are prepared by keeping optimum silica fume and Laterite soil constant for M1, M2, M3, M4, M5 and M6. Physical and mechanical experiments of M30 grade of concrete were used to analyze how these materials affected such attributes as compressive strength, split tensile strength, and flexural strength. Key Words: Laterised concrete, Ground granulated blast furnace slag (GGBS), Silica fume, Laterite soil.

Design and Development of a Low Cost Laterite Sieving Machine

Sieving has been an essential process in the use of laterite for building, agriculture, etc. However, manual laterite sieving results to drudgery, fatigue, and time wastage during the processing. The method of laterite sieving is still being done manually in some parts of the country and therefore labour intensive. This is because a lot of Small and Medium Scale Entrepreneurs cannot afford the existing sieving machines because of their cost implications and availability. The simple aim of this paper is to develop a laterite sieving machine that will enhance the efficient sieving of laterite sand to be used in the construction/housing sector and also to reduce drudgery. This paper presents the design of an efficient laterite sieving machine that was developed with locally sourced materials with ease of maintenance amongst other advantages. The machine motion was designed with the concept of crank and slider mechanism. The machine is powered with a 2.43kW, 2600 RPM diesel engine and with the appropriate pulley ratio, the machine operated at a speed of 440RPM with an operating rate of 300kg/hour. The machine component parts include prime mover, Hopper, driving/driven pulley, belt guard, sieving unit and the machine frame. Several fabrication techniques such as welding, machining, etc. are adopted for the fabrication of the machine. Dry laterite sample was tested with the machine for operational effectiveness and the result shows that the machine has a sieving capacity of 300kg/hr and sieving efficiency ranging from 92 - 97%. The fabricated laterite sieving machine performed well with high sieving efficiency, reliability, durability with an estimated cost of 646, 684.00 Nigerian Naira.
 The study was carried out in Akure, Ondo State, Nigeria. A performance evaluation was carried out on the machine and the sieving efficiency is 96% was achieved.

Influence of Thermal Activation and Silica Modulus on the Properties of Clayey-Lateritic Based Geopolymer Binders Cured at Room Temperature

In this study, a laterite soil which is a locally available material in many parts of the world was used as the aluminosilicate precursor. The main objective of this study is to investigate the effect of calcination temperature on physicochemical properties of the resulting geopolymers synthesized from calcined laterite soils. In order to produce the geopolymer binders, the laterite soil was activated thermally through calcination (from 550 to 750 °C) and the resulting calcined laterite was activated with an alkali activator composed of 8 and 10 M of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) in mass of 0.5. Then, the calcined laterite soils and synthesized geopolymer products were analyzed using X-ray diffraction (XRD), Brunner-Emmet-Teller (BET), Fourier Transform Infra-Red (FTIR), X-Ray Fluorescence (XRF), thermogravimetry (TG), scanning electron microscopy (SEM/EDX), and differential scanning calorimetry (DSC). The results from this study indicate that increasing the calcination temperature from 550 to 750 °C resulted in the transformation of phases and an increase in the reactivity of the laterites, resulting in material with improved properties. The use of laterite calcined at 750 °C and activated with 8 M NaOH solution resulted to an increase in the 28 days compressive strength by 35.3 MPa when compared to laterite calcined at 550 °C. Increasing the concentration of the NaOH solution was also found to yield higher material performance. Microstructural investigations showed a heterogeneous compact and dense structure resulting from high polycondensation much pronounced with the rise of calcination temperature from 550 to 750 °C.

Effect of Curing Temperature on the Mechanical Strength of Alkali Activated Laterite Geopolymeric Samples

A huge amount of carbon dioxide is released in the Portland cement production process. A large quantity of greenhouse gases is produced because of the significant amount of energy consumption via making bricks through firing. Using the pozzolanic sources containing the aluminosilicate and alkaline reagents, a new type of green materials called geopolymeric materials are produced with quite lower environmental hazards. The use of laterite as an iron-rich aluminosilicate material has a high potential for building materials. In this study, the effect of the curing temperature and characteristics of the alkaline reagent including the concentration of sodium hydroxide solution and the water-glass to sodium hydroxide mass mixing ratio on the mechanical strength of the laterite-based, oven-cured geopolymer samples was investigated. The results showed that the curing temperature had a significant effect on the compressive strength of the laterite-based geopolymer samples so that with a 15°C change at the curing temperature, the compressive strength of the samples could be multiplied and a sharp increase in the mechanical strength could occur. Also, according to the results of this study, the 6 M sodium hydroxide is recommended for the construction of the laterite-based geopolymer materials with low cost and relatively high strength, and for the construction of higher-strength building materials, the 14 M sodium hydroxide is recommended.

Low-cost material as active substrates for the removal of phosphorus in synthetic effluents: a proposal for social treatment technology

Considering the importance of the development of simplified technologies and social control in sanitation actions, this study investigated the use of laterite for phosphorus removal in synthetic effluents, through adsorption, as a low-cost alternative with the possibility of reusing the generated effluent, for communities where access to sanitation is limited. In the experimental design, the variables pH, contact time, granulometry and laterite dosage were used. Factorial planning was used for processing, for optimization and desirability. It was observed that the removal efficiency did not have significant interference in relation to the pH and contact-time variables. The kinetics of the batch experiments showed that the ideal contact time was 6.4 hours and pH of around 4. The adsorption capacity was plotted against equilibrium concentration for the Freundlich and Langmuir isotherms. The Langmuir isotherm was more suitable for phosphorus adsorption. The results show that laterite was effective in phosphorus adsorption in the order of removal of 87%, showing itself to be a potential adsorbent material.
 Keywords: laterite, phosphate adsorption, simplified effluent treatment.

Assessment and mapping of the high background radiation anomaly associated with laterite utilization in the south coastal region of Kenya

Laterite is commonly used in Kenya and other tropical countries as an aggregate material for road paving. However, the use and relocation of laterite and other geological materials from high background radiation areas (HBRA) may increase exposure to ionizing radiation in areas that were originally at background radiation levels. We present the results of an in-situ radiometric survey conducted at sites associated with laterite utilization around the Mrima Hill HBRA and adjoining environs along a section of the main road in south coastal region of Kenya. The goal of this study was to determine the levels of primordial radionuclides, as well as to assess and map the associated radiation exposure due to the modified radiation field resulting from the use of laterite in the region. It was found that air absorbed gamma dose-rates on parts of the road and side road intersections (median values are 326 ± 52 and 987 ± 138 nGy h−1, respectively) range 4–14 times higher than the adjoining areas. This anomaly was attributed to elevated levels of 238U and 232Th (activity concentrations range 202–1452 Bq kg−1 and 315–1579 Bq kg−1, respectively) measured adjacent to the laterite roadbeds. In addition, results from the energy dispersive X-ray fluorescence analysis of lateritic soils showed that Th correlates positively with monazite constituent elements namely P, La, Ce and Nd suggesting that the laterite used for road paving in parts of the region was sourced from Mrima Hill.

Study of Laterite Stone as Building Material

The paper deals with understanding of laterite as a building material and study of their various properties. Observations of the structures built in laterite blocks would be the part of the study. The research aimed at providing appropriate use of laterite as a building material. The rising construction cost and drive towards locally available material have fuelled a demand for this product in recent years. The basic properties of laterite should be studied. This will thus help in understanding it better as a building material. The method used for research was survey and observation analysis. Literature reviews, interviews and case study based inferences and findings showed that Laterite is found in tropical regions and the structures built in laterite are mostly of load bearing. The study also showed that laterite can be considered as a very good construction material for building various structure like residential buildings, bridges etc.

Use of laterite as a sustainable catalyst for removal of fluoroquinolone antibiotics from contaminated water

Although there is a growing interest in Fenton oxidation processes based on natural catalysts, the use of laterite soil to promote sequential adsorption/oxidation treatments of fluoroquinolone antibiotics has been scarcely investigated. In this work, the ability of an african laterite containing goethite and hematite to remove flumequine (FLU), used as a representative compound of fluoroquinolone antibiotics, was evaluated under dark and UVA irradiation. Batch experiments and liquid chromatography analyses showed that the presence of laterite can enhance FLU removal from heavily contaminated water through both sorption and oxidation reactions (up to 94% removal of 77 μmol L−1 of FLU and 72% of mineralization). The heterogeneous reaction rate is dominated by the rate of intrinsic surface chemical reactions including sorption and oxidation of FLU, and light-induced reduction of FeIII sites to produce FeII. Based on the probe and scavenging experiments, OH radicals were mainly involved in the heterogeneous oxidation reaction. The photo-assisted Fenton process showed a high efficiency of FLU removal even in the presence of a second fluoroquinolone antibiotic, norfloxacin (NOR), which can be co-found with FLU in affected environments. Determinations of kinetic rate constants and total organic carbon (TOC) for five sequential adsorption/oxidation cycles showed that laterite exhibited no deactivation of surface sites and an excellent catalytic stability. This cost-effective and environmentally friendly remediation technology may appear as a promising way for the removal of fluoroquinolone antibiotics from multi-contaminated waters.

Models for predicting compressive strength and water absorption of laterite-quarry dust cement block using mixture experiment

The use of laterite, quarry dust and recycle aggregates etc as replacement for sand in sandcrete block production is common trend in developing countries like Nigeria. Most resources and research efforts are committed towards conducting trial test with a view to coming up with mix production that will yield the desired property. This work presents a mathematical model for predicting the compressive strength and water absorption of laterite-quarry dust cement block using augmented Scheffe's simplex lattice design. The statistical models developed can predict the mix proportion that will yield the desired property. The models were tested for lack of fit and found to be adequate. Keywords : compressive strength, laterite, mixture experiment, quarry dust, water absorption

Effect of Different Coarse Aggregate Sizes on the Strength Characteristics of Laterized Concrete

The high cost of conventional concrete materials is a major factor affecting housing delivery in developing countries such as Nigeria. Since Nigeria is blessed with abundant locally available materials like laterite, researchers have conducted comprehensive studies on the use of laterite to replace river sand partially or fully in the concrete. However, the works did not consider the optimum use of coarse aggregate to possibly improve the strength of the laterized concrete, since it is normally lower than that of normal concrete. The results of the tests showed that workability, density and compressive strength at constant water-cement ratio increase with the increase in the coarse aggregate particle size and also with curing age. As the percentage of laterite increases, there was a reduction in all these characteristics even with the particle size of coarse aggregate reduction due to loss from the aggregate-paste interface zone. Also, when sand was replaced by 25% of laterite, the 19.5mm and 12.5mm coarse aggregate particle sizes gave satisfactory results in terms of workability and compressive strength respectively at 28 days of curing age, compared to normal concrete. However, in case of 50% up to 100% laterite contents, the workability and compressive strength values were very low.

Use of laterite for the removal of fluoride from contaminated drinking water

The effects of different operational variables on the mechanistic function of laterite in removal of fluoride have been investigated. Thermodynamic parameters such as free energy change, enthalpy, and entropy of the process, as well as the sorption isotherm, were evaluated. The extent of solute removal is determined by initial solute concentration, operational conditions, laterite dose, and solution pH. For a fixed set of experimental conditions, a model equation is developed from which the percent removal corresponding to each load of fluoride is determined. The mechanism of fluoride adsorption is governed by the zero point charge of laterite and follows a first-order rate equation. pH has a vital role influencing the surface characteristics of laterite. To simulate the flow dynamics, fluoride solution was run through a fixed bed column. The pattern of breakthrough curves for different influent fluoride concentration, pH, and column bed height was characterized. The column efficiency was tested from the bed depth–service time model. The elution of the retained fluoride was studied and the effectiveness of column operation was determined by the retention–elution cycles.

Removal of some toxic metal ions from water in a batch process using laterite

The potential use of laterite for the removal of some toxic metal ions viz. Cu II , Zn II , Ni II and Fe II from aqueous solution was investigated. The equilibrium was found to attain within two hours. At equilibrium the adsorption capacity was determined to be 73.6, 85.7, 44.6 and 90.5 μmol g -1 respectively for Cu II , Zn II , Ni II and Fe II with particle size of 300 mm, dose of 1.0 g, agitation speed of 400 rpm and 303 K. The applicability of the process was determined by equilibrium, kinetic, thermodynamic and isotherm parameters. The interference and tolerance limit of different foreign ions on metal ions removal was evaluated. The removal efficiency >70% was obtained in spiked as well as bulk samples. The process was found to be efficient, easy and cost effective. Laterite as an adsorbent can be recommended as an alternative to active carbon for metal ions removal.

Constructed wetlands for waste water treatment: the use of laterite in the bed medium in phosphorus and heavy metal removal

Constructed wetlands for waste water treatment: the use of laterite in the bed medium in phosphorus and heavy metal removal

Laterite as a catalyst for the hydrotreatment of heavy Oil. I. Identification and characterization of a venezuelan laterite

AbstractThe use of laterite as a hydrotreating catalyst has been recently initiated. For this purpose, a careful characterization of the laterite was necessary. Chemical analysis and several physico‐chemical techniques, e. g. XRD, TGA/DTA, IR, show that the laterite studied here consists of aluminous goethite. hematite, gibbsite and titanium oxide. It has also shown a substitution of 22–24% mole of AlOOH in the goethite lattice.

Study on the use of laterite as an iron-making material — Research at Nippon Steel Corporation

Starting in 1955 and for approximately ten years thereafter, Nippon Steel conducted studies on the use of laterite (after the extraction of Cr, Ni, Al, etc.) as a raw material for the production of plain steel. After basic research on the mineral structure, bench scale tests were carried out to study the separation properties of the constituent components and thereby to determine the best process to use. This process was then tested and evaluated in a 1 t/h pilot plant and is indicated in a flow chart. The treatment of Philippine M-2 ore produced a good quality ▪ concentrate containing 62% T.Fe, 0.1% each of Cr, Ni and Na and 2% Al 2O 3. The Fe recovery rate was 82%, the Cr separation rate 95% and the Ni separation rate was 83%. Research was also conducted into the recovery of Cr, Ni, Al and Na.

The Analysis of Temper in Earthenware from Archaeological Sites

This study was submitted in partial fulfillment of the requirements for an MA degree in Anthropology at the University of Otago, Dunedin, New Zealand. This analysis is from pottery refuse shards from two Thai sites excavated in the 1960s. 1. Non Nok Tha, from a site with occupation lasting around 7000 years, excavated by Don Bayard, then at the University of Hawaii. The Archaeological excavation of the site was in two periods, 1966 and 1968. This analysis was from pottery excavated in the second period. From 12 natural layers excavated, eleven cultural levels established three periods of occupation 1. Ban Tha Nen, around 100 miles away, where four levels were established from 17 cultural layers. This analysis was only from pottery in levels two and three. This was from about 300 A.D. to the end of the 15th century. This site was excavated by Ham Parker, University of Otago. Overall, 19 varieties of temper were observed. Some tempers such as laterite, coarse chaff and no temper, were associated with a certain thickness of wares at Ban Tha Nen. The noticeable appearance there in Level three were other small quantities of wares with temper such as soft chaff, and minor sand tempers. But there were consistently large quantities of wares with temper such as the soft sand and ‘clay and sand’. These tempers indicate the majority of pottery level three was locally produced and less sensitive to the varying levels of external contact. Changes in market demand for certain wares were the major cause of variation in temper usages. In contrast, at Non Nok Tha, Period C was a long stable period of occupation with consistent usage of the same tempers throughout the sequence. It was a sharp increase in the use of laterite and hard chaff towards the end of period in levels three and four. This may have coincided with a period of increasing external contact.

機械構造用低炭素鋼の組織におよぼす少量のNi, Crの影響

In the future, with the growing use of laterite are as a raw material for steelmaking, metallic impurities such as Ni and Cr will accumulate increasingly in final products. In more general case the final products may be contaminated with Ni and Cr contained in steel scrap. But there is little information on the effects of small amounts of Ni and Cr on properties of plain carbon steels which are in the greatest demand. From such a viewpoint, the authors investigated the effects of small amounts of Ni and Cr on properties of low, medium and high carbon steels.This paper is concerned with the effects of Ni and Cr on microstructural factors of low carbon ferrite plus pearlite steels. Studies were made for JIS S15C steel, and microstructural factors, such as pearlite fraction, mean ferrite path, condition for CrN-precipitation and critical cooling rate for bainite formation were investigated. Particularly, the condition for CrN-precipitation was discussed with equilibrium state in mild steel, and the free energy equations for CrN-precipitation were presented for the case that Cr and N coexist with Al and Si.