Waste Rice Husk Ash and Waste Rubber Chips Added Light Weight Concrete Paving Blocks: Mechanical Behaviour and Forecasting Strength Properties

The purpose of the study was to use waste rice husk ash (RHA), residual ash generated at the rice husk fuelled clay brick kiln, for manufacturing paving blocks. Strength, durability, water quality of the paved surface run-off and microstructure of specimens were examined. Cement in paving blocks was partially replaced by five percentage of waste RHA: 0%, 5%, 10%, 15%, and 20% (by weight). At 10% waste RHA, paving block structure became denser than the conventional block, and 56-day compressive strength was improved by 18.1% and 26.5% for M15 (Grade 15) and M25 (Grade 25) blocks, respectively. Paving blocks with 10% waste RHA achieved splitting tensile strength and flexural strength greater than that of the conventional blocks. At all waste RHA levels, sulfate resistance was improved, water absorption was ranged 3–6% and British Pendulum Number was found to be higher than 45, satisfying the limits specified in standards. For the run-off, total suspended solids concentration was less than 6 mg/l, turbidity was ranged 2.15–3.57 NTU, conductivity was ranged 74.0–137.0 μs/cm and satisfied the limits in standards. This study concludes 10% of waste RHA without any pre-processing can be used as a cement replacement in paving blocks.

Cement plays a major role in the production of paver blocks. Cement manufacturing industries pollutes the surrounding areas. The main objective of this work is to reduce the use of cement in the concrete paver block by partial replacement with rice husk ash. An experimental investigation is conducted to analyze the compressive strength, water absorption and flexural strength of paver blocks with partial replacement of cement by rice husk ash dumped near Chengapalli, Tiruppur. Rice husk ash were collected from the dump yard and utilized for experimental investigation after doing the initial cleaning process and property study of material. Cement replacement with Rice husk ash were done in proportions of 10% 20%, 30%, 40% and 50% in volume of concrete. Various strength parameters like compressive strength, flexural strength and water absorption were determined. Weight of concrete blocks is considerably reduced with increase in the amount of rice husk ash.

Owing to India’s extensive geographical expanse and diverse topographical circumstances, road transport has emerged as a crucial means of transit in the country. The Indian government is prioritising the enhancement of road transport infrastructure nationwide by allocating substantial capital investments. An eminent concern in India revolves around the insufficient allocation of infrastructure for pedestrians and non-motorized vehicles. An effective approach to tackle this problem is to establish dedicated infrastructure facilities for pedestrians and non-motorized vehicles. Paver blocks are predominantly utilised for the construction of these structures and the most common type of paver blocks used are Concrete Paver Blocks (CPB). Due to the lower strength criteria for these CPB, a diverse array of waste/alternate materials are being utilised in the production of CPB. This study seeks to examine the application of silica fume and rice husk ash as supplemental cementitious materials (SCMs), and coconut shell aggregate and quarry dust as substitutes for coarse and fine aggregates, respectively, in CPB. The study aims to assess the strength, durability, and abrasion properties of environmentally friendly concrete paver blocks. Replacing cement with CSA and QD weakens concrete, whereas adding SCMs like RHA and SF strengthens it. Because CS30QD30R20S10 has somewhat higher strength than CM, the combination of CSA, QD, RHA, and SF may be more environmentally beneficial. Higher CSA and QD concentration increased abrasion loss, presumably due to a weaker matrix. However, SCMs improved abrasion resistance. CS30QD30R20S10 had somewhat less abrasion loss than CM, hence CPB produced with it will function better.

This study investigated the optimal water/binder (w/b) and aggregate/binder (a/b) ratios in producing a concrete paving block. The w/b and a/b ratios in the concrete paving block were optimised using the response surface methodology (RSM), considering the performances of the ultrasonic pulse velocity (UPV), flexural, and compressive strengths. Regression modelling was conducted to represent the relationships between the UPV and compressive strength and the compressive and flexural strengths. Generally, the UPV, flexural, and compressive strengths increased with the increment of w/b ratio and reduction of a/b ratio. The RSM suggested optimal ratios of 0.35 for w/b and 3.50 for a/b, that the paving block could exhibit UPV, flexural, and compressive strengths of 4.11 km/s, 4.13 MPa, and 33.2 MPa, respectively. The predicted values from the RSM varied less than 6% compared to the experimental values. The polynomial regression model could effectively represent the relationship between the UPV and the compressive strength and the relationship between the compressive and flexural strengths of the concrete paving block.

This study examines the suitability of alternate binders and crumb rubber (CR) to produce light weight alkali‐activated concrete (AAC). For this, strength, and durability performance of AAC incorporating CR by partially replacing fine aggregate was studied. To produce AAC, four different binders, including fly ash, rice husk ash (RHA), metakaolin, and bottom ash were used. Fine aggregates were substituted with CR at 0%, 10%, 20%, and 30% for each AAC mix (with different binders). Furthermore, the mixes were prepared using 12 M sodium hydroxide (NaOH) solution, and the ratio of sodium silicate (Na2SiO3) to NaOH was taken as 2.5. The samples were cured at ambient temperature. Strength and durability properties, including permeability through water absorption and acid attack (hydrochloric acid [HCl] and sulfuric acid [H2SO4]), were also checked. Results of this study revealed that the strength decreased with the increase in CR content. Further, this decrease was high at 30% replacement but strength was satisfactory. AAC showed good relationships among compressive, flexural, and split tensile strengths. Similar footprints were observed for permeability results. However, highest water absorption was observed for bottom ash binder (with 30% substitution of CR). Mixes with fly ash and metakaolin binders outperformed the other mixes while comparing the compressive strength of acid exposed samples. Overall, a sustainable and durable light weight AAC can be prepared using 20% CR.

A test programme was carried out to investigate the feasibility of utilising waste tyre crumb rubber as a partial replacement for fine aggregate (river sand) in the precast concrete paver block (PCPB). This study examines the density, compressive strength, split tensile strength, flexural strength, rebound number and ultrasonic pulse velocity of PCPB with waste tyre crumb rubber. A comparison is also made between controlled PCBP (without crumb rubber) and PCBP containing various percentages of crumb rubber. The replacement contents of crumb rubber are 5%, 10%, 15%, 20% and 25% by volume. M40 grade of concrete was used and the experimental investigation was carried out to evaluate the influence of crumb rubber for 7, 28 and 56 days study. The results indicated that there was a reduction in the density, compressive strength, split tensile strength, flexural strength, rebound number and ultrasonic pulse velocity with the increase in crumb rubber content in the concrete mix. The results also revealed that up to 15% crumb rubber replacement by sand volume meets the target strength of 46.60 MPa, meaning that concrete containing crumb rubber content up to 15% is useful for making light weight concrete and is recommended for use in the paver block manufacture.

Waste tyres accumulate very quickly in a landfill as a result of the fast development of the transport industry, and mainly automobiles. The polymeric waste has limited usage and is rarely employed in a highly economic and viable product. A rigid pavement material needs to have high mechanical properties and durability when exposed to aggressive environments. In this research, a combination of waste tyre with rice husk ash and Portland Cement Composite (PCC) as a primary binder was designed to produce concrete that meets the requirements of flexural strength value of the rigid pavement based on the Indonesian Standard from Bina Marga 2018. Eight mixes with a variety of water/cement ratio (0.30-0.40), crumb rubber (2.5-7.5%), and rice husk ash (7.5-10%) were designed in this research. The control mix was PCC concrete. The crumb rubber substituted the fine aggregate content, while the rice husk ash replaced the cement content in concrete. The specimens were cast and subsequently cured in water pond up to 28 days. The mechanical properties of concrete, namely compressive strength and flexural strength were determined for all variations. Based on the results, Mix 1 with w/c ratio of 0.30, crumb rubber of 5%, and rice husk ash of 10%, performed both the highest compressive strength and flexural strength values of 36.38 MPa and 4.53 MPa, respectively, after 28 days. Both values fulfilled the requirements of the Indonesian Standard Bina Marga 2018. It can be concluded that an appropriate combination of crumb rubber and rice husk ash improves the mechanical properties of the concrete and has potential as a rigid pavement material.

A waste tyre is an inorganic rubber waste that is difficult to decompose since it has a complex structure. Utilization of waste tyre as a material to improve elastic properties in rigid pavement construction in peat environment has not investigated yet. The rigid pavement in peat environment needs to be impermeable and posses high elastic properties. This paper presents mechanical properties and porosity of concrete incorporating crumb rubber as an additive in concrete mixture with a variation of 10%, 20%, and 30% by fine aggregates volume. Rice husk ash is added as a filler in various percentage (5%, 10%, and 15%) by cement volume in the mixture. Concrete is produced with a target strength of 35 MPa. In this research, the OPC concrete mix is used as a control mix. Mechanical properties taken were the compressive strength, tensile strength, flexural strength, modulus of elasticity, and porosity at 7, 14 and 28 days. Results show that crumb rubber and rice husk ash addition increases compressive strength, improves elastic properties, i.e., tensile strength, flexural strength, modulus of elasticity, and reduce the porosity of the concrete. It can be concluded that the crumb rubber is potential as an environmentally friendly additive as rigid pavement material in peat environment.

This study examines the utilization of rice husk ash (RHA) and slaked lime as substitutes for a portion of the cement in manufacturing concrete. The RHA was acquired from a nearby source, subjected to calcination at temperatures ranging from 500 to 700 °C, and then passed through a sieve to obtain particles with a size of 150 microns. Concrete mixes were made using Ordinary Portland cement (OPC), fine and coarse aggregates, and water, with different amounts of RHA and slaked lime. The concrete mix design adhered to established standards, with a mix ratio of 1:1.5:3 (cement: fine aggregate: coarse aggregate). The experiment was designed using response surface methods, with RHA, slaked lime, and cement as factors, each having five levels. Concrete cubes were formed using 100 mm steel moulds and then submerged in water to assess their workability. The compressive strength was measured using universal testing equipment after 7, 28, and 90 days of cure. The flexural strength of concrete beams was assessed after 7 and 28 days. Samples were subjected to scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) examination after 28 days. The compressive and flexural strengths increased as the curing period progressed, with the 10% RHA substitution showing the maximum strength. The SEM analysis showed that RHA10 exhibited the maximum concentration of silicon, which corresponds to the recommended 10% replacement level of OPC and meets the concrete specifications specified by ASTM M20 grade. Utilising RHA decreases expenses and minimises the amount of concrete that is discarded. The most effective replacement for OPC was 10% RHA, which produced long-lasting and strong concrete.

Effect of waste rice husk ash (RHA) on structural, thermal and acoustic properties of fired clay bricks

Road pavements generally use asphalt and cement concrete as flexible and rigid pavements. A flexible pavement covering material with concrete paving blocks has been developed for low-traffic road structures. Paving block compressive strength tests still use beam samples; some have used cube samples. Concrete waste and plastic waste can reduce material requirements and support environmental sustainability. Therefore, it is used as a recycled material. This research utilizes concrete waste and plastic waste in the composition of the concrete paving block mixture. Compressive and flexural strength tests with a cement and aggregate ratio 1:3 was used in this study. The aggregate comprises screening, sand, stone ash, recycled concrete aggregate, and plastic waste additives. The test results showed that the concrete paving block test objects in the form of cubes and beams produced different characteristics. Cube-shaped concrete paving blocks make more realistic compressive strength test values. Judging from the results of the compressive strength and flexural strength tests, the addition of plastic decreased the strength of the concrete paving block. Still, the addition of 4-6% plastic waste positively contributed to the value of flexural strength.

This paper for the first time investigates the workability, compressive and tensile strength of concrete containing Fly Ash, Rice Husk Ash and Waste Glass Powder. Seventy six cube specimen (150 150 150 mm were cast with different composition of Fly Ash, Rice Husk Ash ,Waste Glass Powder and steel fibers. The cubes were tested for axial compression and tensile tests. The research also investigated the effect of curing regime on the compressive and tensile strength of concrete cube specimen. The results revealed that the addition of 15 % Rice Husk Ash and 39% Fly Ash increased the workability of 25 % as compared to the controlled concrete. The sample containing 10 % Rice Husk Ash, 10% Waste Glass Powder and 39% micro silica produced worst workability as it decreased the workability up to 5 % of controlled concrete. The results for axial compressive strength shows that the addition of 15% Rice Husk Ash (RHA) and 39% of Fly Ash (FA) in concrete leads to the improvement of compressive strength by 14%. The sample containing replacement of 10% Rice Husk Ash (RHA), 10% waste glass powder (WGP) and 39 % of micro silica (MS) in concrete leads to the improvement by 53.9 for compressive. The replacement of 10% Rice Husk Ash (RHA), 10% waste glass powder (WGP ), 39 % of micro silica (MS) 3% steel fiber in concrete leads to the improvement by 37% for compressive strength. It was observed from the results of tensile strength that the samples containing 15% Rice Husk Ash (RHA) and 39 % of Fly Ash (FA) increased the tensile strength by 24% as compared to the controlled concrete. The sample containing replacement of 10% Rice Husk Ash (RHA), 10% waste glass powder (WGP) and 39 % of micro silica (MS) in concrete leads to an increase of 20% as compared to the controlled ones. Also, the replacement of 10% Rice Husk Ash (RHA), 10% waste glass powder (WGP), 39 % of micro silica (MS) 3% steel fiber increased the tensile strength by 40 % as compared to the controlled concrete sample. Finally, it was concluded that the replacement of 10% RHA, 39% micro Silica, 10% WG in concrete was found to be superior for increasing the mechanical properties of concrete.

The waste generated from the disposal of tyres, i.e., waste rubber, rubber products, and angle scrap is very high in volume raising serious environmental concerns. The disposal of this waste has become an environmental concern that needs to be attended to as quickly as possible. The effect of partial replacement of waste fine crumb rubber with sand are investigated on the cement concrete specimens. Due to the wide use of concrete in construction, the application of crumb rubber as a material of concrete would provide an efficient way of disposing the enormous amount of waste that is generated from scrap tyres. In this study, concrete with crumb rubber replacement 3, 6, 9, 12, and 15% is adopted. The objective of this paper is to establish the applicability of crumb rubber as a promising substitute to fine aggregate in conventional concrete. The potential advantage of using the crumb rubber in concrete is revealed through the tests such as compressive strength, split tensile strength and flexural strength. Even though the compressive strength of concrete is reduced to some extent in comparison to conventional concrete by replacing the crumb rubber by fine aggregate but the results showed a substantial increase compared to target compressive strength until 6% replacement.

The background of this study is based on the increasing problem of plastic waste in Indonesia, which has a negative impact on the environment. This study aims to evaluate the utilization of Low-Density Polyethylene (LDPE) polymer waste as a substitute for fine aggregate and rice husk ash as a substitute for cement in making Paving blocks using conventional methods. This study will look at the effect of material substitution on compressive strength and water absorption. The experimental process involves shredding LDPE polymer waste, making Paving block mixtures, and testing mechanical properties. The results showed that the addition of LPDE to the paving block mixture would cause a decrease in strength of 0.8632 MPa for every 1% LDPE used. If added with 10% use of rice husk ash, then every 1% use of LDPE will cause a decrease of 0.6425 MPa. For water absorption, there was an increase of 0.11% for every 1% LDPE mixing and 0.23% for every 1% LDPE mixture with 10% rice husk ash. The price obtained from the variation of LDPE usage of 5%, 10%, 15%, 20% plus 10% rice husk ash is cheaper than the price of using standard materials according to the basic price of the Lampung region in 2022. The price difference is 36%, 33%, 29%, 26% respectively. The use of LDPE waste and rice husk ash in the manufacture of paving blocks not only reduces the amount of plastic waste but also has the potential to make a significant contribution to the development of a more sustainable construction industry and supports efforts to reduce plastic waste in Indonesia. Abstrak Latar belakang penelitian ini didasari oleh permasalahan sampah plastik yang semakin meningkat di Indonesia, yang berdampak negatif terhadap lingkungan. Penelitian ini bertujuan untuk mengevaluasi pemanfaatan limbah polimer jenis Low-Density Polyethylene (LDPE) sebagai subtitusi agregat halus dan abu sekam padi sebagai subtitusi semen dalam pembuatan paving block menggunakan metode konvensional. Penelitian ini akan melihat pengaruh dari subtitusi material terhadap nilai kuat tekan dan penyerapan air. Proses eksperimen melibatkan pencacahan limbah polimer LDPE, pembuatan campuran paving block, dan pengujian sifat mekanis. Hasil penelitian menunjukkan bahwa penambahan LPDE pada campuran paving block akan menyebabkan penurunan kekuatan sebesar 0,8632 MPa setiap penggunaan 1% LDPE. Jika ditambahkan dengan 10% penggunaan abu sekam padi maka setiap penggunaan 1% LDPE akan menyebabkan penurunan 0,6425 MPa. Untuk daya serap air , terjadi kenaikan sebesar 0,11% untuk setiap 1% pencampuran LDPE dan 0,23% untuk setiap 1% campuran LDPE dengan 10% abu sekam padi. Harga yang didapatkan dari variasi penggunaan LDPE 5%, 10%, 15%, 20% ditambah dengan Abu sekam padi 10% lebih murah dari harga penggunaan material standar sesuai dengan basic price wilayah Lampung Tahun 2022. Selisih harganya masing - masing adalah 36%, 33%, 29%, 26%. Pemanfaatan limbah LDPE dan abu sekam padi dalam pembuatan Paving block tidak hanya mengurangi jumlah limbah plastik tetapi juga berpotensi memberikan kontribusi signifikan terhadap pengembangan industri konstruksi yang lebih berkelanjutan dan mendukung upaya pengurangan limbah plastik di Indonesia.

Strength, durability, and environmental properties of concrete utilizing recycled tire particles for pavement applications