Rice Husk Content Research Articles

Use of rise husks to improve the efficiency of MICP-based soil improvement technique

Biogrouting has been identified as the best alternative approach for the conventional cement and chemical grouts. Among the various types of biogrouting techniques, microbial induced carbonate precipitation (MICP) has been recently recognized as a promising pathway for producing biogrout material, hence densifying the weak soils. In MICP, calcium carbonate (CaCO3) biocement is produced through biochemical reactions induced by the urease enzyme. The efficiency and productivity of MICP can be further improved by introducing various additives, including fibers, organic polymers, powders, waste materials, etc. In this research, rice husk was sustainably incorporated into the MICP process, and (i) the effect of the rice husk content, (ii) the concentration of the cementation solution and (iii) the treatment time on the unconfined compressive strength (UCS) of the sandy soil were investigated at the laboratory-scale. Cementation solutions with higher concentrations exhibited a higher UCS values than solutions with lower concentrations. Interestingly, the content of rice husk had a marked influence on the UCS, and the optimum rice husk content was 15%. Compared to that of the control sample (0% rice husk), a threefold greater UCS was obtained for 15% of the rice husk content sample. The outcomes further suggested that longer treatment with lower concentration of cementation solution was the best combination for achieving effective cementation within the sand matrix. Rice husk acted as the template for CaCO3 crystals to nucleate while promoting the efficient formation of CaCO3, indicating that the rice husk is an excellent additive to improve the efficiency of the MICP biocementation in a sustainable way.

Mechanical and thermal properties of rice husk/glass fiber/polylactic acid composites

AbstractPolylactic acid (PLA) composites reinforced with rice husk and glass fiber can improve the properties in the aera of the material for vehicle application. In this work, the PLA composite was made and its properties were evaluated using scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). SEM observed that the polymer matrix contained a uniform dispersion of 10 wt% rice husks. The tensile strength and bending strength of the composite are 45.8 and 48.2 MPa, respectively, which are 52% and 41% higher than that of the base material PLA. TGA revealed that the thermal stability of the composite deteriorated with increasing rice husk content. The DTG curve indicated that the incorporation of rice husk and glass fiber led to a reduction in the maximum degradation rate of the PLA matrix. As a result, the thermal degradation of the PLA composite exhibited enhanced stability. The average apparent activation energy (Ea) of the composite, determined using the Friedman (FD), Flynn Wall Ozawa (FWO), Starink (ST), and Kissinger (KS) models, falls within the range of 90 to 120 kJ mol−1.Highlights Silane coupling agent was used to improve the interfacial compatibility of fillers. The synergistic action of rice husk and glass fiber fillers enhances the mechanical properties of polylactic acid composites. The mean apparent activation energy (Ea) of the composite was calculated using four models, with values in the range of 90 to 120 kJ mol−1. The Flynn Wall Ozawa and Starink models showed better stability against temperature changes compared to the Friedman model.

A Systematic Review of Rice Husk Gasifiers: Technology, Performance, and Sustainability

Pursuing sustainable energy solutions has increased interest in utilizing agricultural waste for energy generation. Among these waste materials, rice husk stands out due to its abundance and potential as a renewable energy source. Gasification, a thermochemical process converting biomass into valuable synthesis gas (syngas), offers a promising pathway for harnessing the energy content of rice husk. This systematic review presents a comprehensive analysis of rice husk gasification, focusing on technology, performance, and sustainability aspects. Drawing from a wide range of literature sources, including research studies, technical reports, and advancements in gasification techniques, the review aims to provide a holistic understanding of the field. The review elucidates the different gasifier technologies used for rice husk gasification, discusses performance metrics evaluating gasification efficiency, gas composition, and energy yield, and examines the sustainability implications of the technology. It also analyzes the influence of rice husk characteristics on gasification outcomes and identifies trends, innovations, and persistent challenges within the domain. This review improves rice husk gasification research by categorizing and synthesizing. Researchers, politicians, and industry stakeholders looking to understand the technology's potential and limitations might benefit from its findings. This evaluation helps guide decision-making and promote rice husk gasification innovations as the globe transitions to sustainable energy.

Cellulose nanocrystals extracted from rice husk using the formic/peroxyformic acid process: isolation and structural characterization.

Cellulose derived from biomass is a renewable resource with numerous applications. Using formic/peroxyformic acid at atmospheric pressure, cellulose nanocrystals (CNC) were isolated from rice husk (RH) in this study. This method was an excellent way to get rid of lignin and hemicelluloses from RH. The cellulose was subsequently acid hydrolyzed by H2SO4 (64%) for 30 minutes at 45 °C. The chemical and microstructure analysis showed that the lignin and hemicellulose contents of raw RH had been eliminated, and the crystallinity content of CNC was 67.16%. According to transmission electron microscopy (TEM) morphological analysis, CNC measured 19 ± 3.3 nm in diameter, 195 ± 24 nm in length, and 10.2 ± 6.8 in aspect ratio. The thermal stability of RH and CNC was also investigated using thermogravimetric analysis (TGA). These encouraging findings demonstrated the potential for reusing RH agricultural waste to create CNC and include nanocomposites as a reinforcing material.

EVALUATION OF MEDIA AND COMPOSTING DURATION ON THE GROWTH AND YIELD OF CONTAINERIZED TOMATO: AN APPROACH TO SUSTAINABLE FOOD PRODUCTION

In Nigeria, agricultural land faces constant depletion due to continuous cropping and competition from urban development. Urban areas suffer from severe land scarcity as available land is utilized for industrial and recreational purposes. Smarter, sustainable farming methods are essential to conserve agricultural soil and maintain crop yield. Thus, an experiment was conducted from December 2016 to June 2017 to investigate the impact of different composting media and durations on containerized tomato cultivation. Four media compositions were tested, including rice husk dust, topsoil, poultry manure, and river sand, in various ratios. The experiment involved composting the media for either eight or six weeks. Results showed that tomato growth increased over time and varied among treatments. Media significantly influenced growth parameters, with T4 performing the best overall. However, T3 yielded the highest fruit weight due to its high topsoil content. Soilless medium (T1) performed poorly due to low nutrient content and slow decomposition of rice husk. Composting duration alone did not significantly affect tomato growth and yield, but the interaction of media and composting duration revealed that T2 composted for eight weeks yielded the best results.

Effect of Rice Husk and Wood Flour on the Structural, Mechanical, and Fire-Retardant Characteristics of Recycled High-Density Polyethylene.

Given the rising consumption of plastic products, it is becoming imperative to prioritize the recycling of plastic items as a solution to reducing plastic waste and environmental pollution. In this context, this research focuses on assessing the impact of incorporating rice husk and wood flour into recycled high-density polyethylene (rec-HDPE) to analyze its mechanical properties, flammability, and thermal stability. The combined rec-HDPE content of wood flour and rice husk varied between 0% and 20%. The rec-HDPE content of maleic anhydride grafted polyethylene (MAPE) was fixed at 3%. Mechanical characteristics such as flexural, tensile, and impact strengths were assessed. Cone calorimetry (CC) tests, limited oxygen index (LOI) tests, and horizontal and vertical burning tests were performed to determine the flammability or fire retardancy of these composites. On the other hand, to characterize the thermal characteristics of these composites, thermogravimetric analysis (TGA) was used. To further characterize the fluctuation in these characteristics, scanning electron microscopy (SEM) and infrared spectroscopy (FTIR) studies were carried out. The mechanical characteristics were found to be increased in response to adding rice husk or wood flour. An 8% increase in tensile strength and a 20% increase in elastic modulus enhancement were recorded for a 20% rice husk-added composite. SEM revealed the reason for the variation in tensile properties, based on the extent of agglomeration and the extent of uniform distribution of fillers in rec-HDPE. Following these lines, the 20% rice husk-added composite also showed a maximum increase of around 6% in its flexural strength and a maximum increase of 50% in its flexural modulus. A decrease in impact strength was recorded for rice husk and wood flour-reinforced composites, compared with unreinforced rec-HDPE. Hybrid composites displayed a lack of mechanical strength due to changes in their nature. FTIR tests were performed for a much more elaborate analysis to confirm these results. Twenty percent of rice husk-added rec-HDPE displayed the best thermal properties that were tested, based on TGA and derivative thermogravimetric (DTG) analysis. This 20% composite also displayed the best fire-retardancy characteristics according to UL 94 tests, cone calorimetry tests, and limited oxygen index tests, due to the barrier created by the silica protective layer. These tests demonstrated that the incorporation of both fillers-rice husk and wood flour-effectively enhanced the thermal, mechanical, and fire-retardant attributes of recycled HDPE.

Extraction and Characterization of Bio-Silica from Sri Lankan Traditional Rice Husks and Evaluation to TLC Application

Rice husk (RH) is one of the most abundant agricultural wastes, but can be identified as a useful bio resource. Gonabaru, Kahawanu, Patchaperumal, Dahanala and Suwandel are five immerging traditional rice varieties, competing with genetically improved rice in Sri Lankan rice market. Ash content of RHs of traditional rice varieties (>20.0%) was comparatively higher than genetically improved rice. It was identified that additional acid washing step was essential to improve the purity of bio silica. Mineral impurities such as Na, K, Ca, Fe and Mn were determined using atomic absorption spectrometer (AAS). High silica content was extracted from RHs of traditional rice varieties (>23.0%) than that of improved variety, BW 364 (~16.2%). The functional groups present in Rice husk ash (RHA) and rice husk silica (RHS) were determined using Fourier transform infrared (FTIR) analysis. The potential application of purified RHS was observed by preparing and analyzing the thin layer chromatography (TLC) in comparison with commercial TLC silica.

ENGINEERING CHARACTERIZATION OF GUM ARABIC BONDED PARTICLE BOARD MADE FROM RICE HUSK AND SAWDUST

The Particle board (PB) was developed using Rice Husk (RH) and Sawdust (SD) with Gum Arabic (GA) resin as binder. The aim of the research work was to explore the engineering viability of GA bonded particle board made from agro-industrial wastes for sustainable environment. It was also to investigatealternative to the high-in-demand conventional particle board made from wood and urea melamine or amino-formaldehyde which is known to be carcinogenic. The RH/GA/SD materials used to produce samples were cheap and locally sourced. For the experiment, the rice husk (RH) content was kept constant although at 65%but the sawdust (SD) and gum arabic (GA) were varied at percentage levels of 5/30%, 10/25%, 15/20%, 20/15%, and 25/10%. After characterization the density of the Pb samples ranged from 447.71 Kg/m3 to 698.84Kg/m3. The compressive, split tensile and flexural strengths ranged from 2.24 to 23.31N/mm2, 1.52 to 3.04 N/mm2 and 1.776 to 4.752N/mm2 respectively. Modulus of elasticity ranged from 33.20 to 158.4N/mm2. The results showed that all the mechanical parameters tested met the requirement of the standards, except for moisture intrusion. The maximum value of water absorption was 7.62% for 2 minutes’ immersion in water as against 0.66% and 3.45% in 12 minutes recommended by European standards. The produced particle board is considered structurally viable in that at its ultimate strength it can serve as load-bearing in spite of relatively low density. To mitigate against water absorption, use of wax, veneer and paints can be introduced.

Thermochemical Characterization of Rice-Derived Residues for Fuel Use and Its Potential for Slagging Tendency

Rice is the most important cereal in Asia. However, it also results in the generation of large quantities of rice-derived residues (i.e., rice straw and rice husk). Due to the residues richness in lignocellulosic components, they potentially have considerable value in material and/or energy production without illegal burning in open fields. This work focused on investigating the thermochemical properties and inorganic/metal element contents of rice straw and rice husk. The former included proximate analysis, calorific value, thermogravimetric analysis (TGA) and energy dispersive X-ray spectroscopy (EDS). The latter covered the ten elements most relevant to their slagging/fouling indices. The results showed that they are suitable for energy use as biomass fuels, but rice husk was superior to rice straw because of the high silica content in the rice husk and the significant contents of potassium, sulfur and phosphorus in the rice straw. Using several slagging and fouling indices, the evaluation results were also consistent with their contents of inorganic elements or oxides. To increase the fuel properties of rice-derived residues, they could be pretreated with alkaline leaching, thus causing lower emissions of particulates and reduced slagging tendency when co-firing them with coal in industrial boilers.

The use of rice husk particles to adjust the rheological properties of 3D printable cementitious composites through water sorption

This work presents an experimental investigation on the use of rice husk fine particles to produce 3D printable cementitious composites. Rice husk was chosen as a potential component for printable composites due to its high-water sorption capacity and its high amount of embodied biogenic carbon. These key features were used to adjust the fresh-state properties of the composites, required for the printing process, while decreasing its environmental impact. In this study, a high-early strength Portland cement was used, and the rice husk content varied from 5 to 15 %, in mass of solids. The hydration kinetics was studied using isothermal calorimetry while the rheology of the composites was evaluated using a viscosimeter equipped with a Vane spindle. The rheological parameters were used to assess the buildability and printability of the concrete mixtures. Results demonstrated that rice husk delays the hydration, but this effect can be mitigated through alkaline treatment of the particles. The rheological tests showed that the water sorption by the particles plays an important role on the fresh properties of the composites. The use of rice husk increased the initial yield stress from 176.5 Pa to 2251.9 Pa, and the structuration rate from 6.03 Pa/min to 23.4 Pa/min, when 15 % of particles were used. Finally, rice husk particles increased the maximum object height and reduced the maximum time between layers, which proved the feasibility of using high water sorption biomass particles to produce 3D printable cementitious composites.

The Effect of Rice Husk as Additive in Injection Molding Process

This study investigated the moldability and the mechanical properties of bio-composite with rice husk as natural reinforcement. Natural materials that are abundant in nature can be used as reinforcement for polymer materials. Natural materials as reinforcement in plastic materials were used to obtain alternative materials in an injection molding process. With rice husk, polypropylene, and MAPP, four compositions of bio-composite materials were made and used as raw material injection molding process. The moldability from this material was observed through visualization of the product. The mechanical properties of the materials were observed by the tensile strength and impact test on the injection molding product. The result showed that these materials could be injected to form ASTM D638-03 Type V tensile test and ASTM D256-04 impact test specimens. Visually, the more rice husk on the bio-composite material, the darker the product color. The differences in tensile strength values decreased along with increased rice husk content. All bio-composite materials had roughly the same tensile strength value and were lower than polypropylene, except RH-5%. The impact value of bio-composites was lower than polypropylene impact value and tended to decline along with the increase in the rice husk content. Scanning electron microscope (SEM) analyzes were done on the fracture side of the impact specimen. Microscale voids decreased and were rarely found by adding rice husk to the material bio-composite. On the other hand, rice husk breakage and pullout phenomenon on bio-composite material were found.

Rice Husk as a Pore-Forming Agent: Impact of Particle Size on the Porosity and Diametral Tensile Strength of Porous Alumina Ceramics

This study describes the porosity and particle size effects of rice husk pore former on the diametral tensile strength of porous alumina (Al2O3) ceramics. Porous Al2O3 ceramics with high porosity and sufficient diametral tensile strength were successfully prepared by the pore-forming agent method using rice husk (RH) as the pore former according to the sample formulation Al2O3-xRHy (where ‘x’ denotes the particle size range in µm and ‘y’ denotes the percent weight content (wt%) of RH). The thermogravimetric analysis (TGA) and X-ray diffractometer (XRD) results revealed that silica was retained as rice husk ash in the developed porous Al2O3 after the decomposition of the starting rice husk pore former. Microstructures of the as-prepared porous Al2O3 ceramics having different RH additions exhibited hierarchical pore structures with increased particle size of the pore-forming agent. Porosity increased with larger particle size range of rice husk where the Al2O3-63RH5 demonstrated the least porosity (44.2 vol%), while the highest porosity (70.9 vol%) was demonstrated by the Al2O3-125–250RH20. The diametral tensile strength of the RH-shaped porous alumina ceramics declined from 16.97 to 0.65 MPa with increased particle size of the rice husk.

Ethanol Production Comparison from Agricultural Waste of Cellulose Source Within Hydrolysis Hcl and Cellulose Enzyme

The production of Ethanol has been utilized through the process of cellulose isolation from agricultural waste such as corn husk, rice straw and rice husk. Isolation of cellulose with pretreatment delignification using, NaOH 2% to produces cellulose of corn husk 16,6921 g (22,25%), rice straw 16,9021 g (22,53%) and rice husk 16,3691 g (21,85%) then analyzed the functional groups using FT-IR and SEM analysis. Cellulose as much as 2 g is hydrolyzed using HCl 30% and cellulase enzymes to obtain sugar that is qualitatively tested with Benedict and Tollens reagent and quantitatively tested with Luff Schoorl method and produces highest sugar content of rice husk 8,64% and 10,95%. The next stage sugar of hydrolysis will be fermented using yeast (Saccharomyces cerevisiae) with 6 days, and then distilled at a temperature of 78-80oC. Ethanol was calculated by the potassium dichromate oxidation method to gave highest result from agricultral waste of ethanol chemical 5,97% and enzymatic 6,89% is rice husk.

Utilization of rice husks as a fuel for gasification – A review

Rice husks are widely known as a fuel for electricity generation through gasification technology. Rice husks are abundant in agricultural countries, especially in South and Southeast Asia. Although it is useful, if it is not handled properly, rice husks can become dangerous waste. Abandoning them at large amounts of wastes in fields can damage soil and water contaminated, increase the emission of methane due to its natural decomposition, and produces rainwater leachates. Rice husks are produced from 20% of the weight of rice produced. The content of rice husk is cellulose (50%), lignin (25-30%), silica (15-20%), and moisture content (10-15%). Rice husks have low bulk density by the range of 90-150 kg/m3. From studies obtained equivalent ratio (ER) is range 0.15-0.35, gasifier temperature was conducted at 600-900°C. This paper presents a review of studies conducted on rice husk gasification. Recent research has been reviewed, and key findings are highlighted based on each result of syngas produced. Syngas produced from gasification has a low heating value of 1373.18 kcal/Nm3 – 2603 kcal/Nm3. Syngas compositions are CO, CO2, CH4, and H2. Rice husks syngas are used as a fuel to the internal combustion engine (ICE) as the prime mover to produce electricity.

Tribological performance of eco-friendly friction materials with rice husk

The present paper addresses the tribological behaviour of new eco-friendly brake friction materials with rice husk (RH). Three formulations with different RH content (0%, 6% and 12%) were developed and subjected to the SAE J2522 test procedure, plus an extra high-temperature section, through a laboratory-scaled braking tribometer. At 300 °C, RH acted holding wear debris and improving wear resistance due to the formation of large contact plateaus. At 550 °C, RH's organic compounds degraded, leading to a greater material fade. Formulation 6% RH outperformed the others, showing the lowest wear. In this case, the effect of the hard and temperature resistant silica outweighed the degradation of the organic compounds.

Study on selective laser sintering process and investment casting of rice husk/ Co-Polyamide (Co-PA hotmelt adhesive) composite

The current available wood-plastic materials used for selective laser sintering (SLS) investment casting are often poor in fluidity in molten state, which is not easy to flow out the shell mold. This led to a large amount of residual ash in mold after heating and lowered the quality of the sintered parts. In this article, the Co-Polyamide (Co-PA Hotmelt adhesive) and rice husk powders (RH) were proposed as the feedstock of the rice husk (RH)/CO-PA composite (RHPA) for SLS. CO-PA with good fluidity was used as the matrix and RH powder as the additive materials. This paper aims to optimize the SLS processing parameters and determine the optimal ratio of RHPA parts manufactured by SLS. Through this work, an orthogonal experimental method of five factors and four levels was used to determine the optimum SLS parameters for the RHPA SLS test. The scan spacing, scan speed, laser power, layer thickness, and preheating temperature are chosen as main SLS affecting factors of this study. The synthesis weighted scoring methods were used to conclude the optimal combination of SLS parameters of RHPA i.e., scan spacing = 0.15mm, scan speed = 2m/s, laser power =16W, layer thickness = 0.25 mm and the preheating temperature = 74°C. Moreover, the influence of RH content on the mechanical properties, dimensional accuracy, and the residual ash content of RHPA parts was determined. When the ratio of RH powder on RHPA is 10 wt %, the bending strength of the sintered parts will reach 2 MPa. Besides, the residual ash content of RHPA parts after heating step was lower (1.1881%) and the tolerance level is CT5. Thus, the dimensional accuracy in X, Y, and Z directions of 10 wt % RHPA SLS parts is 99.79%, 98.71%, and 97.9%, respectively; and the surface of casting was smooth and clear details.

Novel fabrication of SiO2/Ag nanocomposite by gamma irradiated Fusarium oxysporum to combat Ralstonia solanacearum

The bacterial wilt is a global destructive plant disease that initiated by the phytopathogenic Ralstonia solanacearum. This study display a novel biofabrication of silica/silver nanocomposite using Fusarium oxysporum-fermented rice husk (RH) under solid state fermentation (SSF). The biofabricated nanocomposite was characterized by XRD, UV–Vis. spectroscopy, DLS, SEM, EDX elemental mapping, and TEM analyses as well as investigated for anti-R. solanacearum activity. Response surface methodology was also processed for optimizing the biofabrication process and improving the anti-bacterial activity of the fabricated nanocomposite. Maximum suppression zone of 29.5 mm against R. solanacearum was reached at optimum RH content of 6.0 g, AgNO3 concentration of 2.50 mM, reaction pH of 6.3, and reaction time of 2 days. The anti-R. solanacearum activity of the fabricated nanocomposite was further improved by exposing the F. oxysporum strain to a gamma irradiation dose of 200 Gy. In conclusion, RH recycling under SSF by F. oxysporum could provide an innovative, facile, non-expensive, and green approach for fabricating SiO2/Ag nanocomposite that could be applied efficiently as an eco-friendly antibacterial agent to combat R. solanacearum in agricultural applications. Moreover, the developed method could serve as a significant platform for the designing of new nanostructures for broad applications.

Combustion Characteristics of A Wood Pellet Made of Albizia Chinensis and Rice Husk

<p>To reduce dependence on fossil fuel, biomass, e.g. the wood pellet, has been developed in recent years. Indonesia has an abundant source of biomass, e.g. wood and rice husk. This work investigates the combustion characteristics of the wood pellet made of Albizia Chinensis and rice husk. The analyzed combustion properties are ignition delay time, the mass of residue, combustion duration, combustion rate, maximum flame temperature, During the experiment, the rice husk content varies between 0 to 50%. As the rice husk content increases from 0 to 50%, the ignition delay time increases from 6 to 9.9 seconds, the mass of residue increases from 21.2 to 45 % and the combustion rate decreases from 0.55 to 0.52 g/min. In addition, higher rice husk content also decreases the maximum temperature.</p>

Novel Foaming-Agent Free Insulating Geopolymer Based on Industrial Fly Ash and Rice Husk.

This study highlights the synthesis of a new thermal insulating geopolymer based on the alkaline activation of fly ashes. A porous geopolymer material can be prepared without the addition of a foaming agent, using high ratio solution/ashes (activating solutions used are water, sodium or potassium hydroxide). In order to increase the porosity of the material and to make it more ecological, rice husks are incorporated into the formulation. The geopolymer materials were prepared at room temperature and dried at moderate temperature (105 °C) by a simple procedure. The microstructural characteristics of these new porous geopolymers were assessed by optical microscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and X-ray fluorescence (XRF). Infrared spectroscopy (FTIR) was used to confirm the geopolymerisation. The effect of the ratio solution/ashes and the percentage of the rice husk addition on thermal and mechanical analysis was evaluated. An insulating material for a solution/ashes ratio of 0.9 and a rice husk content of 15% having a λ value of 0.087 W/(m·K), a porosity of 61.4% and an Rc value of 0.1 MPa was successfully prepared.

Investigating compressive strength of building blocks for varying content of marble dust and rice husk

An investigation was performed using soil compacted masonry bricks that have been manufactured by combining marble dust particles (MDP) and rice husk (RH). Marble dust is a byproduct of the manufacturing of marble rocks. Additionally, a little amount of rice husk (RH), a fibrous substance which is also a bio-waste material obtained from rice processing mills, was utilized to make the masonry bricks. Typically, the trash employed in this research harm the environment and generates recycling issues. Unlike red bricks and cement bricks, which necessitate pre-treatment and additional water requirement, marble powder stabilized masonry blocks require merely solar drying, resulting in less carbon emissions and water conservation. Attributed to the prevalence of calcium in the MDP, increasing the MDP percentage in the blocks leads in an enhancement in compression strength. Additionally, it boosts the block's dry density, as MDP could not intake moisture and may readily plug the gaps left by the soil and rice husk. Rice husk percentage was modulated between 0.5 and 1.0 percent, and 2.0 percent, and MDP concentration was adjusted between 10 %, 20 %, 30 %, and 40 % in conjunction with the soil. The findings indicated that MDP at 30 % and RH at 1.0 percent significantly improved the compression characteristics of the masonry blocks.