Enhancement of the Mechanical, Self-Healing and Pollutant Adsorption Properties of Mortar Reinforced with Empty Fruit Bunches and Shell Chars of Oil Palm

Hermawan, Dede; Budiman, Ismail; Febrianto, Fauzi; Subyakto, Subyakto; Pari, Gustan; Ghozali, Muhammad; Bahtiar, Effendi Tri; Sutiawan, Jajang; Azevedo, Afonso Rangel Garcez de

doi:10.3390/polym14030410

Cited by 5 publications

(2 citation statements)

References 30 publications

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“…This study measured that the specimen's average air-dry moisture contents ranged from 15.92% to 17.13%, in line with some research reports on wood [17,[56][57][58][59] or bamboo [60][61][62][63][64][65] located in Bogor (ID), but wetter than the equilibrium moisture content (EMC) in the subtropical region such as Coventry (UK) [66,67]. The air-dry timber is wetter than mortar [68]. The air-dry specimen's moisture content is compatible with the timber under dry service conditions, such as indoor structures, where the moisture content does not exceed 19%.…”

Section: The Physical Propertiessupporting

confidence: 83%

Comparing the Building Code Sawn Lumber’s Wet Service Factors (CM) with Four Commercial Wood Species Laboratory Tests

Bahtiar

Denih

Priadi

et al. 2022

Forests

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Indonesian Wooden Building Code (SNI 7973-2013) has adopted the National Design Specification (NDS) for Wood Construction since 2013. A periodic harmonization of the building-code-designated values (i.e., reference design values and adjustment factors) with the experimental data of commercial wood species is necessary. This study aimed to compare the building code’s wet service factors (CM) with the laboratory test of some commercial wood species. Since wood is weaker when its moisture content is high, the wet service factor (CM) must adjust the sawn lumber reference design values if the building serves in wet or aquatic environments. Four commercial wood species, namely pine (Pinus merkusii), agathis (Agathis dammara), red meranti (Shorea leprosula), and mahogany (Swietenia mahagoni), were subjected to mechanical property tests. To calculate the empirical CM values, the mechanical properties tests were conducted on air-dry and wet wood. Instead of testing the full-sized timber, which contains the growth characteristics and defects, this study chose clear-wood specimens to resemble the boundary condition of the ceteris paribus (other things being equal). The wet (water-saturated) specimens were immersed in water for 65 days, and the test was carried out when the specimen was still immersed. The test arrangement imitated the submerged wood as the worst-case scenario of the wet environment where the construction serves, rather than green or partially immersed timber. As many as 40 specimens were tested to compare each mechanical property’s wet service factor; thus, this study reported 200 specimens’ laboratory test results. The empirical CM values to adjust the modulus of elasticity, modulus of rupture, shear strength parallel-to-grain, tensile strength parallel-to-grain, and maximum crushing strength (CM = 0.59, 0.76, 0.65, 0.73, and 0.67, respectively) were significantly lower than SNI 7973-2013 designated values (CM = 0.9, 0.85, 0.97, 1, and 0.8, respectively). The empirical CM for the compression stress perpendicular-to-grain at the proportional limit and that at the 0.04″ deformation (CM = 0.66) were slightly lower than the designated values (CM = 0.67), although they were not significantly different. This study resulted in lower empirical CM values than the designated ones, which found that the building code lacked conservativeness. The lacked conservativeness is mainly attributed to the building code’s recent choices, e.g., (1) the wet service environment basis is the green timber rather than the fully water-saturated one, and (2) the ratio of near minimum (5% lower) distribution value is chosen as the CM value rather than the average of wet timber’s mechanical property divided by the air-dry one. This study proposes changing both recent choices to alternative ones to develop more safe and reliable designated CM values.

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Section: The Physical Propertiessupporting

confidence: 83%

Comparing the Building Code Sawn Lumber’s Wet Service Factors (CM) with Four Commercial Wood Species Laboratory Tests

Bahtiar

Denih

Priadi

et al. 2022

Forests

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“…The raw adjusted digitized data and the estimated curves were plotted together to visually identify their goodness of fit. The coefficient of determination (R 2 ) and mean square error (MSE), well known in all regression analysis types (i.e., simple linear [43][44][45][46][47][48][49], multiple linear [50][51][52][53], and non-linear [20,[54][55][56][57][58][59][60]), were also calculated to measure the model's goodness of fit. Higher R 2 and lower MSE values indicate the better-fit model.…”

Section: Annual Tree Ring Elliptical Curve Fittingmentioning

confidence: 99%

Biological Rotation Age of Community Teak (Tectona grandis) Plantation Based on the Volume, Biomass, and Price Growth Curve Determined through the Analysis of Its Tree Ring Digitization

Bahtiar,

Kim,

Iswanto

2023

Forests

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Teak (Tectona grandis) is a deciduous tree producing a popular, expensive, fancy timber with versatile utilization. The teak population and its habitats in the natural forest have been decreasing consistently; thus, the IUCN Red List classifies it as an endangered species. Teak tree logging from its native natural forest is banned, and commercial teak timber can only be harvested from the plantation. People plant teak on their private lands or in the community forest to meet the increasing demand. This study analyzed the annual tree rings of a teak disk taken from the community plantation and aimed to determine its biological rotation age. Tree ring interpretation provides the increment and growth that are mandatory fundamental components of knowledge in sustainable forest management. It may also decipher the tree’s biography, which contains information about past climate and future predictions responding to climate change. All of the disk’s annual tree rings were digitized, transformed, and then curve-fitted using an elliptical polar form of non-linear regression. The best-fitted curve estimation of every annual tree ring was employed to determine their age-related diameter and basal area, and then allometric equations estimated the above-ground biomass and clear-bole volume. The continuous and discrete formula fit the growth curve well, and this study determined that Chapman-Richards is the best fit among others. The growth curve, current annual increment (CAI), and mean annual increment (MAI) were graphed based on the clear-bole volume, above-ground biomass, and log timber price. The CAI and MAI intersections result in 28, 30, and 86 years of optimum harvesting periods when the growth calculation is based on volume, above-ground biomass, and log timber price, respectively. These results identified that the teak plantation is a sustainable and highly valuable asset to inherit with long-term positive benefits. The sociocultural provision of teak plants as an inheritance gift for the next generation has proven to be economically and ecologically beneficial.

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Activated Carbon for Cosmetics Applications

Budiman,

Amirta,

Yuliansyah

et al. 2024

Biomass-Based Cosmetics

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Enhancement of the Mechanical, Self-Healing and Pollutant Adsorption Properties of Mortar Reinforced with Empty Fruit Bunches and Shell Chars of Oil Palm

Cited by 5 publications

References 30 publications

Comparing the Building Code Sawn Lumber’s Wet Service Factors (CM) with Four Commercial Wood Species Laboratory Tests

Comparing the Building Code Sawn Lumber’s Wet Service Factors (CM) with Four Commercial Wood Species Laboratory Tests

Biological Rotation Age of Community Teak (Tectona grandis) Plantation Based on the Volume, Biomass, and Price Growth Curve Determined through the Analysis of Its Tree Ring Digitization

Activated Carbon for Cosmetics Applications

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