Five Indonesian wood include sengon (Falcataria moluccana), manii (Maesopsis eminii), pinus (Pinus merkusii), duabanga (Duabanga mollucana) and maniani (Flindersia pimenteliana) were treated with polystyrene. The purpose of this study was to determine the physical and mechanical properties of treated wood. Air-dried samples were placed under vacuum at 600 mmHg for 30 minutes, which was followed by immersion in monomer styrene and pressure at 10 kg/cm2 used varied for 30, 60, and 90 minutes respectively. The wood samples were then wrapped in aluminium foil and placed in an oven at 103±2 °C for 24 hours. Furthermore, the aluminium foil was removed and the samples were weighed for polymer loading calculation. The test of impregnated wood conducted by refers to the British Standard BS 373:1957, comprised of moisture content, density, water absorption, shrinkage swelling, modulus of rupture, modulus of elasticity, and hardness. Results showed that wood treatment with polystyrene could improve the physical and mechanical properties of wood.

No abstract

Lignocellulosic materials such as wood and bamboo have special characteristics when carbonized at high temperature. For example the electrical conductivity of wood and bamboo increases when carbonized at temperature of 800°C or higher. This property can be used for developing smart materials such as fiber reinforced concrete which has function as sensors for load, damage or temperature. In this experiment, betung bamboo (Dendrocalamus asper) was carbonized at different temperatures and times of carbonization. The purpose of this experiment was to observe the effect of temperature and time of carbonization on the properties of bamboo carbon. Bamboo in the form of particles were carbonized at temperature of 400°C for 300 min and continued at temperatures of 700, 800, or 900°C for 45, 60, or 90 min. Carbon properties such as yield, fixed carbon, volatile matters, and ash content were determined. Structure properties were studied by X Ray Diffraction (XRD), morphological properties were observed by Scanning Electron Microscope (SEM), and electrical conductivity was measured using LCR meter. Result shows that increasing temperature and time of carbonization have significant effects on the structure and other properties of bamboo carbon. Carbonization at temperature of 800°C for 60 min was considered as an optimum condition.

The utilization of waste as soil stabilization materials is a solution to reduce the amount of waste and improve the building materials quality. This research is using Spent Bleaching Earth (SBE) materials from the palm oil industry waste. SBE can be reused to be pozzolan materials. This research aimed to investigate the SBE waste effect as an admixture on clay stabilization used 10% Clean Set Cements (CS-60) on density and California Bearing Ratio (CBR). A combination of CS-60 and SBE waste was expected to increase the CBR value of clay. Furthermore, SBE waste would decrease cementitious material for clay stabilization. Variation comparison of Clay : CS-60 : SBE on ST03, ST04, and ST05 were 67.5% : 10% : 22.5%; 45% : 10% : 45% and 22.5% : 10% : 67.5% respectively. The test was conducted on water content, density, and load penetration based on SNI 1744:2012. Generally, the CBR value of subgrade and improved subgrades oil with the moderate and good category are about 5-20%. As a result, the CBR value of ST 01 as original clay and ST 02 as clay with 10% CS-60 was 3.24% and 5.01%, respectively. Using SBE waste as an admixture material on clay stabilization increased CBR value better than clay stabilization used CS-60. ST03, ST04, and ST05 with CBR's value were 5.39%, 8.52%, and 17.99%, respectively. Furthermore, the density value decreased when SBE waste is used. Keywords : california bearing ratio, clay, clean set cement, spent bleaching earth, stabilization.   ABSTRAK Pemanfaatan limbah sebagai bahan stabilisasi tanah lempung merupakan solusi dalam mengurangi jumlah limbah dan meningkatkan mutu dari bahan bangunan. Penelitian ini menggunakan material Spent Bleaching Earth (SBE) dari limbah industri pengolahan minyak kelapa sawit. SBE dapat dimanfaatkan sebagai material pozzolan. Penelitian ini bertujuan untuk mengetahui pengaruh limbah SBE sebagai bahan tambah pada stabilisasi tanah lempung yang menggunakan 10% Clean Set Cements (CS-60) terhadap densitas dan California Bearing Ratio (CBR). Kombinasi limbah SBE dengan CS-60 diharapkan mampu meningkatkan nilai CBR tanah lempung. Selain itu, juga mengurangi penggunaan bahan berbasis semen untuk stabilisasi tanah lempung. Variasi perbandingan tanah lempung : CS-60 : SBE yang digunakan pada sampel ST03, ST04, dan ST05 berturut-turut 67,5% : 10% : 22,5%, 45% : 10% : 45% dan 22,5% : 10% : 67,5%. Pengujian yang dilakukan meliputi pengujian kadar air, densitas, dan penetrasi beban yang mengacu pada SNI 1744:2012. Secara umum, nilai CBR tanah dasar dan tanah timbunan dengan kategori sedang dan baik berkisar antara 5-20%. Hasil penelitian ini memperlihatkan bahwa sampel ST01 yang berupa tanah lempung asli memiliki nilai CBR 3,24% dan sampel ST02 yang berupa tanah lempung yang distabilisasi dengan 10% CS-60 menghasilkan nilai CBR 5,01%. Penambahan limbah SBE dapat meningkatkan nilai CBR dengan nilai yang lebih tinggi bila dibanding dengan hanya distabilisasi dengan CS-60, hal ini terlihat pada sampel ST03, ST04, dan ST05 dengan nilai CBR berurutan sebesar 5,39%, 8,52%, dan 17,99%. Selain itu, penambahan limbah SBE juga akan menurunkan densitas dari tanah lempung.   Kata kunci : california bearing ratio, clean set cement, spent bleaching earth, stabilisasi, tanah lempung.

No abstract

Cement board is a composite made from lignocellulosic biomass or other materials and bonded with cement, that has advantages such as fire and termite resistance, and can use for some purposes. The cement board’s quality is affected by the biomass’s chemical components, especially hemicellulose and extractives. Treatment to reduce the content of these two compounds in fiber can improve the cement board quality. This study aimed to evaluate the cement board’s properties reinforced with coconut coir fiber (CCF). Pretreatment was performed on fibers by soaking in cold water for 24 hours and soaking in hot water for 1 hour to reduce the chemical compounds. The ratio between fiber-cement used varied to 1:2.75, 1:3.0, and 1:3.25 based on weight, while magnesium chloride (MgCl2) uses at 2.5% of cement weight as an accelerator. The mixtures hand-matt formed and cold-pressed for 24 hours, with a density of the board was 1.25 g/cm3. The panels kept for 28 days before tested. Physical and mechanical tests conducted according to ISO 8335-1987. Results showed that the cement board’s physical and mechanical properties made from CCF soaked in hot water at the ratio fiber to the cement of 1:3.25 is the best properties compared to others.

This study aims to produce mortar through the addition of oil palm shells (OPS)-activated charcoal and oil palm empty fruit bunch (OPEFB) hydrochar, which has high mechanical properties, self-healing crack capabilities, and pollutant adsorption abilities. The cracking of mortar and other cementitious materials is essential in anticipating and reducing building damages and ages due to various reasons, such as chemical reactions, foundation movements, climatic changes, and environmental stresses. This leads to the creation of self-healing mortar, which is produced by adding reductive crack size materials to form calcium carbonate (CaCO3) and silicate hydrate (3CaO.2SiO2.2H2O, CSH). One of these materials is known as activated charcoal, which is obtained from oil palm shells (OPS) and oil palm empty fruit bunches (OPEFB) fibres. This is because the OPS-activated charcoal minimizes crack sizes and functions as a gaseous pollutant absorber. In this study, activated charcoal was used as fine aggregate to substitute a part of the utilized sand. This indicated that the utilized content varied between 1–3 wt.% cement. Also, the mortar samples were tested after 28 days of cure, including the mechanical properties and gaseous pollutant adsorption abilities. Based on this study, the crack recovery test was also performed at specific forces and wet/dry cycles, respectively, indicating that the mortar with the addition of 3% activated charcoal showed the best characteristics. Using 3% of the cement weight, OPEFB hydrochar subsequently varied at 1, 2, and 3% of the mortar volume, respectively. Therefore, the mortar with 3 and 1% of OPS-activated charcoal and OPEFB hydrochar had the best properties, based on mechanical, self-healing, and pollutant adsorption abilities.

Corn stalk (Zea mays L.) can be used as an alternative material in the manufacture of particleboards. However, particleboards made from corn stalks has inferior mechanical properties which could not meet the Japanese standard (JIS A 5908: 2003). Such performance can be improved by adding other material which possesses high strength value, such as bamboo sembilang (Dendrocalamus giganteus Munro). This study examined properties of cornstalk particleboard which was added into bamboo sembilang fibers in various compositions. Urea formaldehyde and phenol formaldehyde were used as binding agent with 10% adhesive content. Composition of fiber mixtures between corn stalk and sembilang bamboo were set in 100 : 0; 75 : 25; 50 : 50; and 25 : 75. The targetted density of particleboard was set at 0.80 g/cm 3 . Mechanical properties of the produced particleboards were evaluated according to JIS A 5908:2003 standard. Results showed that particleboard produced using composition of 25% corn stalk and 75% sembilang bamboo bonded with phenol formaldehyde had better mechanical properties than those of the other mixture raw materials and adhesives. Additional high strength of lignocellulose material such as bamboo is one alternative to enhance mechanical properties of cornstalk particleboard.