Properties of Shotcrete According to Accelerator Types and Mixing Ratios

Shotcrete should be attached to the ground and should have stable strength for a long-term. It should develop strength earlier for rapid work. Therefore, in this study, three types of accelerators—aluminate, cement mineral, and alkali-free—were selected and mixed to secure the initial strength. Depending on the type and mixing rate of each accelerator, slump, air amount, and compressive strength were used to evaluate the basic properties, boiling water absorption test, and chloride ion penetration resistance to conduct durability analysis. The mixing of aluminate-based and cement-mineral-based accelerators was effective in improving the initial strength, and alkali-free accelerator was effective in improving the long-term strength. The mixture to which accelerators were not mixed showed the highest water-tightness.

Effect of Plasticizers on the Physicochemical properties of Bioplastic Extracted from Banana Peels

Plasticizers are the binding substances used to increase the elasticity of materials. In this research work, bioplastic is extracted from banana peels using various plasticizers such as, glycerol, urea, distilled water and glucose. The prepared bioplastics were characterized by using Fourier-transform infrared spectroscopy (FTIR) spectroscopic analysis which showed that the peak at 3355 cm-1 indicate the H-bonding formation between N-H urea and starch. The physicochemical properties such as water absorption test, soil decomposition and load test of synthesized bioplastics were analyzed at ambient temperature. The water uptake analysis showed that bioplastic absorbs water for up to 4 days without being decay. The load test showed that urea plasticized bioplastic has a high tensile strength of 2.3 KPa. The result revealed that the bioplastic with glucose as a plasticizer showed the effective result in water uptake and soil decomposition test whereas the urea plasticized bioplastic showed relatively good tensile strength.

Effect of Lightweight Aggregate Impregnation on Selected Concrete Properties

The impregnation of lightweight aggregate (LWA) is an alternative method to its pre-moistening, which is used to limit the loss of fresh concrete workability due to the aggregate’s ability to absorb a great amount of mixing water. The aim of this study was to access the effectiveness, by pre-coating LWAs with cement paste, in modifying the properties of concrete composites. Two types of lightweight aggregates (Lytag and Leca) characterized with a relatively open-structure shell were selected. The other changeable parameters taken into consideration in this research were: LWA size, initial moisture of aggregate before the impregnation process and type of cement paste applied as an impregnant. Sixteen concretes prepared with pre-moistened and pre-coated lightweight aggregates were subject to a density test in different moisture conditions, a water absorption test and a compressive strength test. On the one hand, the pre-coating of LWAs with cement paste resulted in a relatively slight increase in concrete density (by up to 19%) compared to the pre-moistening of LWAs. On the other hand, it caused a very significant reduction (by up to 52%) in the composite’s water absorption and an incomparably greater growth (by up to 107%) in compressive strength. The most crucial factors determining the effectiveness of impregnation of LWAs with cement pastes in improvement of composite properties were the aggregate type and its size. The composition of impregnating slurry and the initial moisture content of LWA before pre-coating also mattered.

EFFECT OF SALT-WATER AGING ON THE MECHANICAL PROPERTIES OF FLAX-WOVEN FABRIC-REINFORCED EPOXY COMPOSITES

In this investigation four varieties of plain derived-irregular basket-woven-flax fabric-reinforced epoxy (F-E) composites pre-treated with alkali and trimethoxymethylsilane (ATS) were prepared with a hand lay-up process by varying their weight fraction of fiber loadings (0; 25; 35; 45) w/%. A water-absorption test (salt water) as per ASTM D 570-98 was performed over the fabricated composites and studied its consequences on their static mechanical properties (such as tensile, flexural, impact and interlaminar shear strength) in accordance with the ASTM standards. The results revealed that salt-water-soaked ATS-treated F-E composites exhibited poorer mechanical properties than unsoaked ones. Moreover, this study elaborated the kinetics of water absorption and showed that the moisture-absorption rate depends on the weight fraction of fibre content. Furthermore, scanning electron microscopy (SEM) disclosed fiber splittings and severe damage at the fiber-matrix interface as experienced by soaked F-E composites.

Sustainable Production of Roofing Tiles Using Glycerine Pitch as An Alternative Binder

A large quantity of glycerine pitch (GP) generated from the oleo-chemical industry has led to significant environmental issues when it is disposed of without proper treatment. This study investigated the possibility of utilizing glycerine pitch as an alternative binder in the production of roofing tile, namely GP-RT. The percentage of GP incorporated by weight of tile ranges from 3 – 9 %. A transverse strength test was performed on the tiles in dry and wet conditions to investigate their durability in harsh conditions. A water absorption test was performed to determine the water uptake of the tiles produced. The specimen with the greatest flexural strength was achieved when 7% of GP was utilized. The mechanical properties of the tile can be enhanced when GP was mixed with a similar amount of used cooking oil (UCO), which achieved the greatest strength (4389 N and 9.48 MPa) when 5% of GP and 5% of UcO were used for the tile’s production. The water resistivity of the tiles can be enhanced by the coating process. The lowest percentage of water absorption (2.82%) and the greatest wet transverse strength (2746 N) were achieved when the tile was coated with a layer of UCO via the immersion method. Conclusively, the full replacement of cement with GP as an alternative binder is possible. The incorporation of multiple waste materials (GP, UCO, and fly ash) in tile production is a feasible attempt to reduce the disposal of these waste materials to landfills, thus preserves a greener environment for future generations.

Water Absorption of Incorporating Sustainable Quarry Dust in Self-Compacting Concrete

In construction industry nowadays, self-compacting concrete (SCC) is a concrete technology innovation which gives more benefits over conventional concrete. SCC was invented to improve concrete durability without using any vibrator while placing it into formwork. In order to conserve natural sand, quarry dust (QD) as a waste and sustainable material has been incorporated to replace fine aggregate in SCC. In this study, conventional concrete and quarry dust in self-compacting concrete (QDSCC) mixes consist of 0%, 10%, 20%, 30%, 40% and 50% QD were prepared. The workability test was conducted to determine the performance of fresh concrete and ensuring all the QDSCC properties follow the acceptance criteria for SCC. Meanwhile, the hardened concrete specimens were water cured for 7, 28 and 60 days to conduct water absorption test. This research aim is to determine water absorption of incorporating sustainable QDSCC. Thus, it resulted that 50% of QDSCC has achieved the lowest water absorption of QDSCC as compared to other dosages. Finally, sustainability in concrete technology can be promoted by incorporating QDSCC.

Analysis and Optimization of Hybrid Soil Properties for Gel Based Roof Tiles

Our current 21st century has seen more drastic changes in terms of environmental conditions due to global warming, climate change and deforestation. This has shown a great rise in the global temperature throughout the world. Normally, the roof top of a building is provided with tiles to protect the structural components and to create a comfortable environment. The tiles can be made of materials like clay, concrete, fly ash, lime etc. Due to the prevailing environmental challenges, there is a need for the tiles to be made as with more energy efficient material that supports thermal insulation and cost effectiveness. Aerogel and hydrogel are the gel based product that are used in our current work to enhance the thermal insulation property of the tiles. Various tests such as water absorption test, wet and dry cycle test, bending strength test, thermal conductivity test, wear and tear test are carried out on the tile to quantify its characteristics. All the above shows better value than the normal commercial tile product.

Analysis and Optimization of Hybrid Soil Properties for Gel Based Roof Tiles

Our current 21st century has seen more drastic changes in terms of environmental conditions due to global warming, climate change and deforestation. This has shown a great rise in the global temperature throughout the world. Normally, the roof top of a building is provided with tiles to protect the structural components and to create a comfortable environment. The tiles can be made of materials like clay, concrete, fly ash, lime etc. Due to the prevailing environmental challenges, there is a need for the tiles to be made as with more energy efficient material that supports thermal insulation and cost effectiveness. Aerogel and hydrogel are the gel based product that are used in our current work to enhance the thermal insulation property of the tiles. Various tests such as water absorption test, wet and dry cycle test, bending strength test, thermal conductivity test, wear and tear test are carried out on the tile to quantify its characteristics. All the above shows better value than the normal commercial tile product.

Exploring the Properties of Mortar Containing Incineration Fly Ash

Fly Ash (FA) is one of the waste materials generated from the combustion of solid waste through incinerator and contains hazardous substances. Further treatment to the ash needs to be done to avoid further environmental destruction. As an alternative solution for this problem, FA is used as a replacement material for cement in the mortar. The main objective of this study is to explore the potential use of FA as partial replacement of cement in mortar. The percentage of FA used to replace the cement in this study is 0%, 5%, 10%, 15% and 20%. Several important tests were conducted to identify main properties of the mortar such as compressive strength, water absorption, density and ultra-pulse velocity. Mortar containing 15% of fly ash has the highest of compression strength which is 35 MPa after 28 days. Besides, the mortar containing 5% of fly ash has the highest result of water absorption test and density test whereas mortar containing 20% of fly ash has the highest value for pulse velocity after 28 days. Thus, mortar containing fly ash has good physical and mechanical properties.

Physico-mechanical and water absorption properties of LDPE/cassava starch film

Plastic waste is a global crisis, and Malaysia is the 8th worst country worldwide for plastic waste. With this trend, growing market demands for green product have imposed pressure on industries to find an alternative to petroleum-based plastic. Degradable plastic is introduced to overcome this limitation. The present work investigates degradable plastic film of low-density polyethylene incorporated with cassava starch (LDPE-CS). The compounding of the LDPE-CS was prepared via pre-mixing, blending, resin crushing, and film hot pressing. Film thickness, tensile strength, elongation, water absorption, and field test were conducted on the LDPE-CS and commercial LDPE (control). Experimental data of LDPE-CS and commercial LDPE films were evaluated and compared. Thickness of LDPE-CS film was 0.18 mm which was 51% thicker than the control film. Tensile strength and elongation of the LDPE-CS were 7.04 MPa and 5.39%, while control film was 12.77 MPa and 921.5%, respectively. The tensile strength and elongation of the LDPE-SC were significantly lower than the control film, which may be due to the weak interface between LDPE and starch. The water absorption test revealed that the LDPE-CS film absorbed water by 4.8%, which indicates its degradability in the water. The field test shows that the LDPE-CS is biodegradable and comparable with the commercial plant polybag in terms of its capability in planting.