Lightweight Building Research Articles

Parameters/configurations adaptability and economic evaluation of PCM for reducing energy demands with lightweight buildings under different climates/cities based on orthogonal experiment and EnergyPlus: China-Japan comparison

Currently, most studies on the energy-saving of PCM are limited to a certain climate or part of PCM parameters/configurations, and the problem of optimal parameters/configurations and suitability of PCM under different climates, energy demands, and energy prices have yet to be well solved. Therefore, the suitability level, the influence degree, and the economic applicability of each PCM parameter/configuration under different climates and energy prices were evaluated in this study by orthogonal experiment and EnergyPlus. Results show that: (1) Different PCM parameters/configurations are required for different climates/cities in reducing energy demands; (2) Factors C (location) and F (orientation) have the highest impact on energy savings, while B (phase-transition temperature range) is the lowest; (3) Higher energy-saving can be achieved by evenly distributing to all orientations (priority: Roof > East > West > South > North) under the same PCM volume (VPCM); (4) PCM can save up to 7.3%-38.06% (China) and 5.17%-20.37% (Japan) for the total loads under the optimal PCM parameters/configurations; (5) the maximum acceptable PCM cost is 5.05 $/kg in China and 8.81 $/kg in Japan based on a 20-year payback period. The research results can provide references for maximizing the PCM application benefits under different climates and energy prices.

Simulation-based assessment of the climate change impact on future thermal energy load and indoor comfort of a light-weight ecological building across the six climates of Morocco

The potential effects of global climate change on buildings are a growing concern worldwide, as rising temperatures can significantly impact their energy performance and indoor thermal comfort conditions. This article examines the impact of global warming across six different climate zones of Morocco by comparing under 2050 RCP8.5 scenario the current and future thermal energy requirements and indoor comfort levels of a light-weight ecologically-designed detached residential house. The reference case study building is in a semi-arid climate of Morocco and empirically validated following the ASHRAE guideline 14, with CV(RMSE) less than 3.2 and NMBE less than 1.4 for the two 38-day monitored thermal zones.The study includes aframework to evaluate the thermal energy needs for maintaining indoor thermal comfort and the overheating intensity triggered by climate change and varying due to spatial scale. Overall, the findings show that Morocco will suffer with differing magnitudes from the temperature increase linked to global warming, which will result in an upsurge in the thermal needs for cooling, particularly in the southern regions of Morocco, and a general reduction in the heating thermal energy needs across the different climates of Morocco, with an annual thermal energy demand change ranging from −2.7% to 17%, depending on the investigated city. This wide variation in thermal energy demand underlines the need to assess the effects of the warming climate in the local context. Besides, under conditions of Air Conditioning (AC) failure, the Indoor Overheating Hours (IOH) increase up to 27% between the current climate conditions and the 2050 climate conditions while indoor temperature changes exceed 1.5 °C during the hottest days of the summer.Strategically, the research study intends to support global efforts to build resilient societies by bringing awareness to how susceptible indoor occupants are to projected warming temperatures. The study also lays the groundwork for prioritizing and assessing adaptation solutions to protect people's health, comfort, and productivity within buildings despite climate change in the most sustainable manner.

Localised pull-through failures of cold-formed steel batten screw connections under combined wind and sub-zero temperature conditions

The utilisation of thin cold-formed steel (CFS) elements is widespread in contemporary lightweight building construction. Roof and wall cladding systems are predominantly made of thin, high-strength steel claddings and battens. Blizzards are predominantly observed in North American countries, resulting in significant roof damage. A localized pull-through failure mechanism, occurring at the batten to rafter/truss screw connections, has been extensively investigated at ambient temperature to comprehend the critical factors that influence the pull-through failure capacities of CFS battens. Nonetheless, the pull-through capacity of CFS battens at sub-zero temperatures has not been examined, and as a result, the performance of the steel cladding systems during blizzards under the combined action of strong winds and sub-zero temperatures remains unknown. To investigate the pull-through failure behaviour and capacities of batten screw connections, an experimental study comprising 96 tests was conducted involving two steel grades and three thicknesses of steel battens and two screw fasteners at sub-zero temperatures. The study was conducted at both ambient and sub-zero temperatures to understand the pull-through failure behaviour and capacities of batten screw connections. Appropriate pull-through capacity equations and associated increment factors were developed to predict the pull-through capacities of batten screw connections that are subjected to the combined effects of high wind uplift loads and sub-zero temperatures.

EAACA net zero roadmap for autoclaved aerated concrete

AbstractThis roadmap sets out a pathway for Autoclaved Aerated Concrete (AAC) products to reach net‐zero emissions by 2050 with the potential to become carbon negative, thereby absorbing more carbon dioxide from the atmosphere than they produce. The roadmap aligns the European Autoclaved Aerated Concrete Association (EAACA) and its members with the objectives of the Paris Agreement to limit global warming to 1.5°C and supports policies to decarbonize Europe's buildings and construction sectors. AAC is a lightweight, yet strong and durable building material that offers ultra‐efficient thermal insulation, optimum fire protection, and a high load‐bearing capacity. With its net‐zero roadmap and the potential to become carbon negative, AAC has a role to play as a building material in helping to reduce the life‐cycle emissions of Europe's buildings. The roadmap sets out the main levers that must be applied to achieve this. We have drawn these from known technologies and have based our net‐zero target on a life‐cycle analysis provided by an independently verified Environmental Product Declaration. As the majority of CO2e emissions come not from the manufacture of AAC itself, but from the manufacture of two key raw materials—cement and lime—the roadmap draws on the decarburization pathways published by global and European cement and lime industry associations. The building and construction sectors account for a significant share of Europe's greenhouse gas emissions that contribute to climate change. Through this roadmap, the EAACA and its members are committed to achieving net‐zero emissions in AAC products by 2050 and supporting the development of a climate‐neutral Europe.

Investigation of effective replacement of sand by waste perlite in AAC production

AbstractAerated concrete is a lightweight building material with excellent thermal and technical properties, relative to strength, excellent workability, and is economically advantageous. The basic composition of raw materials includes lime, cement, silica sand, and aluminum powder. Currently, the usability of secondary raw materials is being investigated in many construction sectors. The usability of secondary raw materials becomes a necessity from an ecological and economic point of view. The elimination of CO2 emissions is currently a major global issue. Secondary raw materials used in the construction industry are most often waste materials produced during the combustion of solid substances. These substances are often accumulated in landfills, which have a negative impact on the surrounding environment. It is necessary to constantly look for new ways of using these waste materials not only in the construction industry. The use of these raw materials reduces the price of the final product. It is advantageous if it also brings about a positive change in the properties of aerated concrete. The article deals with the possibility of replacing part or all of the sand content in the recipe of autoclaved aerated concrete with waste perlite. As part of the experimental verification, the influence of waste perlite filler on physical‐mechanical properties (e.g., bulk density, strength) and changes in microstructure is investigated. Primary sand is replaced by perlite in the amount of 10%, 30%, 50%, and 100% by volume in the experiments. The formation of porous structure, its characteristics, and mineralogical composition, in particular the formation of tobermorite, is also evaluated. The study has brought an interesting finding. The results show that the maximum beneficial amount of waste perlite is 30%. Up to this limit, waste perlite has a positive effect on the even distribution of pores in the matrix, with a zero‐phase content of more than 65%. The compressive strength of the samples with waste perlite increases by up to 22% of the values of the compressive strength of the reference sample.

A novel bionic straw-filled concrete block: compression and heat-transfer performance

To develop economical, environmentally friendly and lightweight building materials, a novel straw-filled bionic concrete hollow block (BCHB) was designed. Compression tests were conducted to determine the compressive strength of the BCHB. Furthermore, the compressive and heat-transfer properties of these blocks were investigated with finite-element analysis, and the following results were observed. (a) The BCHB model did not easily experience local collapse. Instead, it mainly exhibited thin cracks due to shear failure, providing great cracking and collapse resistance, thereby resulting in excellent compressive performance. (b) By reducing the thickness of the short edges of the BCHB models, they exhibited great compressive and thermal insulation performance, making these the preferred BCHBs. (c) The BCHB presented herein was the simplest model of the beetle elytron plate. In contrast to a traditional hollow brick, the BCHB was proven to be a lightweight, fully enclosed brick (block) with a high hollow ratio and could be used as a new non-bearing wall material replacing the traditional type in building construction.

Preparation and properties of lightweight and high-strength building ceramsites with oil-based drilling cuttings pyrolysis residues

With the continuing advancement in China’s exploration and development technologies of shale gas resources, there was a significant increase in shale gas oil-based drilling cuttings. In this paper, oil-based drilling cutting pyrolysis residues (ODCPRs) was used as the main raw material for preparing lightweight and high-strength building ceramsites to eliminate the environmental risks and recycle industrial waste. Firstly, orthogonal experiments were used to study the influences of raw material composition, preheating temperature, preheating time, sintering temperature, and sintering time on the properties of building ceramsites. From the results, the sintering temperature and the content of ODCPRs were discovered to be the key factors affecting the sintering process of ceramsites. Secondly, the influences of sintering temperature and heating rate on the properties of building ceramists were further explored to find the optimum sintering conditions. When the content of ODCPRs in the ceramsite was set to be 50%, the obtained building ceramsites presented excellent properties with particle compressive strength of 6.31 MPa, bulk density of 575.11 kg/m3, apparent density of 1097.24 kg/m3, and the water absorption of 1.89%. Finally, XRD, SEM, TG-DSC, and heavy metal leaching experiments were comprehensively conducted to analyze the composition structure variation and sintering mechanism of the building ceramsite. This paper presents an approach for the recycling, utilization, and disposal of oil-based drilling cuttings in the oil field waste management.

Evaluation of the cooling potential of a vertical greenery system coupled to a building through an experimentally validated transient model

Despite several studies showed that Vertical Greenery Systems (VGSs) have relevant thermal benefits at urban and building scales, researches devoted to investigate the benefits of a green facade through detailed transient thermal simulations are scarce. Furthermore, a study comparing the effectiveness of different plant types is still missing. The present paper aims to fill such gaps by studying the effectiveness of a green façade to improve the thermal behaviour of a well-insulated lightweight building in the Mediterranean area, as well as the perceived indoor thermal conditions, based on both on-site experimental measurements and dynamic thermal simulations with a novel Type in TRNSYS validated through the monitoring campaign. To this aim, two identical full-scale prefabricated modules were installed and monitored at the University Campus of Catania (Italy), differing from each other because one of them hosted a climbing plant species in its west façade. The validated numerical model was then used to appraise the cooling effect of the green façade with two different plant species commonly used in Mediterranean countries (Trachelospermum Jasminoides and Hedera Helix namely). Results show that Hedera helix ensures the best performance when the foliage layer is at an intermediate state of its growing process, while under full foliage development the species investigated show almost the same performance. The incoming heat flux can be strongly attenuated, showing a quite flat daily profile, while the peak value of the internal and external surface temperature of the wall can be reduced by up to 1.6 °C and 10.5 °C, respectively.

Assessing the mechanical, durability, thermal and microstructural properties of sea shell ash based lightweight foamed concrete

The comprehensive properties of waste seashell ash (Oyster shell ash (OSA), Scallop shell ash (SSA), and Mussel shell ash (MSA)) in lightweight foamed concrete (LFC) are needed to explore for using these aquaculture wastes in light-weight building structures. Therefore, this study’s aim is to investigate the fresh, transport, mechanical, pore structure, and thermal properties of OSA, SSA and MSA-based LFC. The seven LFC mixes have been prepared to evaluate the effect of 5, 10, 15, 20, 25, and 30% cement replacement by seashell ash and compared with the control mix. The test findings show that mixes' initial and final setting times increase with the seashell ash substitutions; however, the spreadability and density properties of the fresh test decrease. The MSA ash-based LFC exhibits 0.29–1% lower water absorption than the OSA and SSA ash-based specimens. It was further observed that the 15% MSA replacement in LFC exhibited a maximum of 12.41%, 15.89% and 17.95% enhancement in compressive, flexural and splitting tensile strength compared to the reference mix. Moreover, SEM assessment and pores distribution indicated that up to 15% replacement, the seashell as-based concrete performed better as a pore filler than the rest of the substitutions. The thermal conductivity and specific heat capacity exhibited better performance for all sea shell-based specimens; however, a 15% replacement of MSA seashell-based concrete can be the optimum solution for eco-friendly concrete production considering the overall assessment.

Eco-friendly lightweight composite prepared with a geopolymer and wheat straw

Agricultural waste shows promise for use in lightweight building materials. The combination of a geopolymer and wheat straw (WS) is adopted to produce a kind of eco-friendly lightweight composite. Using WS pretreated with sodium hydroxide (NaOH) and sodium metasilicate (Na2SiO3) solutions, the influence of WS on the properties of the geopolymer–WS composite (GWSC) is investigated. The pretreated WS avoids the retarding effect of the untreated WS on the hydration of the geopolymer and even presents an accelerating effect. Increasing the content of pretreated WS generally results in a reduction in apparent density and strength. A GWSC with an apparent density of 1000–1500 kg/m3 can be prepared, corresponding to a 28-day compressive strength between 5 and 25 MPa. The water absorption linearly increases with the increase in the pretreated WS content, while an appropriate amount of the pretreated WS can enhance the water resistance of the GWSC. A WS/fly ash ratio lower than 8% can produce a GWSC with qualified thermal insulation performance. Alkaline treatment, particularly sodium hydroxide treatment, significantly improves the bonding strength between the fiber and the geopolymer matrix. In addition, pretreated WS saturated with sodium hydroxide and sodium metasilicate solutions is beneficial to the fluidity of the geopolymer–WS mixture and could act as an internal curing agent for enhancing the hydration of the geopolymer.

Preparation of eco-friendly functional lightweight gypsum: Effect of three different lightweight aggregates

Phosphogypsum (PG) is the main solid waste produced in the phosphorous chemical industry, and its resource utilization has become an international problem. Simultaneously, the research and development of lightweight building materials are the key means to achieving building energy conservation and reducing energy consumption. This paper uses hemihydrate phosphogypsum-based cementitious material as the matrix material, and porous structure lightweight aggregate (LWA) as the lightweight component to prepare lightweight gypsum. The properties of the composites were carefully investigated by the examination of mechanical strength, bulk density, drying shrinkage, thermal conductivity, sound absorption coefficient, pore structure, and microstructure. The results show that it can be achieved to obtain lightweight gypsum with a bulk density ranging from 300 kg/m3 to 1500 kg/m3. In terms of thermal behaviour and sound absorption, the lightweight gypsum with pottery sand has the smallest reduction in thermal conductivity, and EPS particles have the largest reduction. Through the introduction of a cavity resonance structure, expanded perlite significantly improved the sound-absorbing performance of the composites, while pottery sand had the least favorable effects. Pottery sand reduces the number of open pores, while expanded perlite increases the number of open pores in the composites. However, the addition of EPS particles can greatly increase the number of closed pores in the composites. This research offers a useful method for the preparation of eco-friendly and functional integrated lightweight gypsum.

Embodied life cycle impacts of lightweight building methods for affordable houses in the USA: Comparison of conventional, circular, and regenerative strategies

The transition to more circular practices in the construction sector offers an alternative to linear processes that are highly polluting and wasteful. Recent life cycle assessment (LCA) studies emphasize the relevance of the end-of-life scenario, highlighting its potential for impact reduction through circular strategies. There is an urgent need to fill the knowledge gap in the LCA literature on reducing the environmental impacts of affordable housing. Whole-building LCAs of three affordable homes built using a variety of lightweight construction methods in the southern United States were conducted to examine the environmental impacts of commonly used construction solutions for single-family affordable housing in the southern US and assess the extent to potential environmental impact mitigation through the introduction of additional circular strategies or the use of regenerative materials. In addition to the conventional as-built scenario, five hypothetical scenarios were considered in this study to evaluate the influence of different end-of-life options, namely, reduced recycling rates, increased recycling or reuse rates, and substitution of conventional insulation or finish materials with equivalent options from regenerative sources. The study aims to identify further opportunities for and limits to impact mitigation. The results show that the design and construction priorities should be (1) promoting proper end-of-life strategies for metals and wood-based materials, (2) replacing non-renewable materials with renewable wood or earth materials, and (3) increasing the reuse rate of materials and diverting construction waste. The study findings will support decision-making processes concerning the design and construction of low-impact affordable single-family homes and the development and implementation of affordable housing policies and regulations, resulting in greater environmental justice and a more equitable and sustainable built environment.

SYNTHESIS AND CHARACTERIZATION OF ENVIRONMENTALLY FRIENDLY PAPERCRETE AS A NEW MORTAR FOR BRICK PANEL INSTALLATION

This research focuses on the development of lightweight and soundproof building materials using waste paper or pulp as a component, with the aim of improving quality of life and reducing environmental pollution. Papercrete, made from unused waste paper, has environmentally friendly characteristics and can be used as the main structure of buildings. The study investigated the effect of pulp on the stress behavior of panels and tested the reusability of paper as a lightweight and eco-friendly brick material. The research method involved experimental procedures, using specialized equipment and materials to determine the properties and performance of different types of concrete mixes. Results indicate that papercrete has potential as an eco-friendly construction material with physical and mechanical properties suitable for reinforcing brick panels. Further research is recommended to investigate the effect of paper chip size on concrete strength under different humidity and temperature conditions, and to analyze the environmental impact of using papercrete as a construction material. The findings suggest that papercrete holds promise as a new and sustainable construction material. Testing papercrete in real-world scenarios could provide valuable insights into its durability and suitability for different applications.

Analysis of the safety impact of mobile rail hydraulic spreader on residential building machines under the system of building machines

The construction industry in China is a labor-intensive industry, but the cheap labor force has begun to change in recent years, with labor costs rising. In some labor exporting provinces, there has even been a "battle for talent.". Based on this, the "14th Five Year Plan" construction industry development plan issued by the Ministry of Housing and Urban-Rural Development proposes to accelerate the coordinated development of intelligent construction and industrialization of new buildings, and promote digital design, intelligent production, and intelligent construction. With the continuous progress of science and technology, the construction industry has also made many technological innovations, and innovative changes have taken place in related technologies. The residential building machine has begun to replace the traditional climbing frame application. Through gradual improvement, the lightweight building machine applicable to this project is only 220T, and the combination of spreader and building machine makes the concrete pouring process more convenient and intelligent, significantly reducing the labor intensity of construction personnel. Based on this, the analysis of the impact of mobile rail hydraulic spreader on the safety of residential building machines is a key factor.

A lightweight building instance extraction method based on adaptive optimization of mask contour

Automatic extraction of building instances from high spatial resolution optical remote sensing imagery is essential for urban infrastructure and smart management. In view of the severe challenges such as intricate building samples, high training overhead and inaccurate mask contours, this paper proposes a region-based, two-stage segmentation model assembled with components of adaptive feature extraction, guided anchoring and iterative subdivision mask, resulting in lightweight extraction of building instances and adaptive optimization of mask contours. We conducted comparison experiments with several classical, state-of-the-art instance segmentation methods on WHU aerial dataset, China city satellite dataset and Inria aerial dataset. The quantitative evaluation demonstrates that our method signally reduces the computational load by at least 34.5%, increases the mask AP on the three datasets by at least 0.8%, 4.6% and 4.1%, respectively, and increases the mean performance (mPC) and relative performance (rPC) under image corruption (12 corruptions and 2 severity levels) by at least 2.4% and 3.2%, respectively. The qualitative evaluation further verifies that our method is more discriminative for features such as color, texture, and shadow, and more adaptable to changes in shape, scale, and distribution and so on. Especially for large-sized buildings, various comparison methods either miss the partial interior area or excessively smooth the mask contour, whereas our method can output complete and accurate masks.

Potential utilization of CO2 foams in developing lightweight building materials

Energy conservation and emission reduction are key focuses in the field of building engineering. In this study, carbon dioxide gas was utilized to develop carbon dioxide foam cement paste materials. The properties of the samples were evaluated by considering the optimal foaming agent, water-cement ratio, foam-grout ratio, and pump speed. To elucidate the carbonation mechanisms, the microstructure and phase composition were analyzed with X-ray diffraction and scanning electron microscopy, respectively. The results demonstrated that the 3-day compressive strength of the test sample was 272.72% higher than that of an air foam cement paste. Additionally, the carbon dioxide foam cement paste exhibited a lower density than ordinary cement-based paste, while its 3-day compressive strength was 14.08% higher than that of the ordinary cement-based paste. Moreover, the price per cubic meter of the carbon dioxide foam cement paste was 19.02% lower than that of the ordinary cement-based paste. The introduction of carbon dioxide foam led to the consumption of hydration products near the voids and accelerated the carbonation reactions of the cement particles around the void-cement interfaces. This promoted the solidification of the foam within the cement paste, ultimately enhancing the early strength of concretion.

Evaluation of phase change materials for a light-weight building in Morocco: Effect of building's volume, window orientation & infiltration

In this study, we will model a light-weight building made of phase change materials (PCMs) to analyze the impact of the building volume, window orientation, and air infiltration on the PCM performance. This is done by calculating the energy savings attained by the use of PCM across all of Morocco. We'll use the commercial Rubitherm panels with RT28HC as a phase change material in this work. Typically, the EnergyPlus simulation engine is chosen to perform the modeling. The impact of building volumes is also evaluated on the PCM activation for light-weight square buildings with different side lengths of 10 m, 9 m, 8 m, and 7 m. Also, we looked at how well the PCM performed in terms of energy savings and thermal regulation at different window orientation placements (south, north, west, and east) and various air infiltration rates (0.5, 1, 1.5, and 3 ACH). This paper's primary objective is to determine the energy savings for the PCM-enhanced building in Morocco, as well as the effect of building volume, window orientation, and infiltration on the PCM capabilities for stabilizing the indoor room temperature. The results show good indoor temperature stabilization during the summer, for the light-weight square building with a south-facing window and no air infiltration. This configuration was able to achieve a total fluctuation reduction of 1303.3 °C for the 10 m building in a semi-arid environment. Besides, a high energy savings percentage of 69.56% was achieved for the PCM-enhanced building with the south-oriented window and air infiltration of 0.5 air change per hour.

Contribution of Lightweight Building Materials to Contemporary Construction

Eski çağlardan başlayıp, günümüz çağdaş yapılarına kadar gelen mimari, insanoğlunun hayatının hep bir köşesinde bulunmuştur. Dolasıyla ihtiyaçlar doğrultusunda, bir örtü düzeneği sayesinde oluşturulan çadırlardan, günümüz gökdelenlerine kadar birçok evre ile yapılar hep gelişmiştir. Sanayi Devrimi’nin de etkisiyle 20. yy içerisinde teknolojinin daha da hızlanması direkt olarak yapı sektörünü de değiştirip, geliştirmiştir. Mimariye katılan yeni malzemelerin uygulanması, yapıda farklı kavramları ortaya çıkarmış ve daha tercih edilir nitelikte olmuştur. Eskiden taşıyıcı özelliğinde olan malzemeler, yapının formuyla strüktürünü ayırıp, mimar ve mühendislerin tasarım dili haline gelmiş ve daha ulaşılabilir çözümler sunmaya başlamıştır. Özellikle 20. yy içinde üretilen ve mevcut yapı stoğunda hala geliştirilmeye devam eden hafif malzemeler, strüktür sistemlerin geldiği son aşama olup, yapılardaki birçok soruna cevap vermektedir. Çelik, katkılı beton, cam sistemler, ahşap sistemler, pnömatik sistemler, membran ve tekstil sistemlerden oluşan hafif strüktür malzemeleri, yapı fonksiyonuna; sürdürülebilirlik, enerji etkinliği, geri dönüştürülebilir malzeme kullanımı, afet durumundaki davranışı, akıllı mimariye katkıları, geçirgen alanlar ve erişilebilir mekân organizasyonları tasarımı gibi birçok avantajı da beraberinde getirmektedir. Bu çalışmada, hafif strüktür malzemelerin yapıların strüktür ve formuna dahil olurken tasarıma etkileri, yapıya ve çevresine katkısı, sürdürülebilir ve geri dönüştürülebilir yapı tasarımına etkisi, deprem ve yangın anında yapıya etkileri, afet sonrası geçici yapılaşmaya katkıları incelenmiştir.

MECHANICAL BEHAVIOUR OF FERROCEMENT LIGHTWEIGHT BANANA FIBRE CONCRETE UNDER UNIAXIAL BENDING

To obtain lightweight and environmentally friendly building materials that can be produced quickly at low cost, among others, can be obtained through the use of natural fiber based ferrocement concrete technology. The use of light weight building materials combined with natural fibers to form structural components is intended to reduce the weight of the building mass but also to protect the environment and benefit banana farmers' income. Ferrocement lightweight concrete (FLWC) can be obtained by partially substituting fine aggregate with pumice sand and by adding banana stem fiber to form a ferrocement lightweight fiber concrete (FLWFC) composition. Compressive and tensile tests on ferrocement lightweight concrete and ferrocement light fiber concrete were carried out at 7, 14, 21 and 28 days, respectively. The test results showed that the optimal composition of FLWC and FLWFC occurred in the substitution of pumice sand by 40% and banana stem fibers with a length of 3 cm by 0.05% of the weight of cement and obtained a concrete mass density of 1437 kg. The compressive strength and tensile strength of FLWC without fiber at 28 days were 8.4 MPa and 2.15 MPa respectively, while FLWC with fiber added increased by about 6%, namely 8.9 MPa for compressive strength and 83% for tensile strength is 3.94 MPa. Flexural tensile strength of Sandwich Wall Panels (SWP) at 28 days of prism-shaped specimens with dimensions of 60 x 30 x 5 cm, 45 x 15 x 4 cm and 30 x 10 x 3 cm respectively 1.60 MPa, 1.86 MPa and 2.4 MPa for FLWC without banana stem fiber. The increase in the flexural tensile strength of the SWP was 40.63% (2.25 MPa), 21.51% (2.26 MPa) and 18.75% (2.85 MPa) respectively in the SWP-FLWC using Banana Fibers (BF) or an average of 26% increase. The size effect of the SWP test object looks significant, that is, there is a tendency that the larger the dimensions of the test object, the smaller the flexural tensile strength value, but on the contrary, the role of banana stem fiber in contributing to the increase in flexural tensile strength is seen to be more significant.

The Growth of Titi Plant (Gmelina moluccana) and Environmental Factors that Affect It

The Growth of Titi Plant (Gmelina moluccana) and Environmental Factors that Affect It