Environment-friendly Building Materials Research Articles

Processing bulk wood into a light-permeable passive radiative cooling material for energy-efficient building

Reducing carbon emissions from building materials production and operation would have a huge impact on the global energy and environment. Wood presents great potential as an environment-friendly building material due to its relatively low carbon emission and cost. However, several issues, including the mechanical anisotropic, extremely low optical transparency, and single function, greatly hinder the further application of wood as a building material. Herein, hybrid wood-derived laminates were dedicatedly fabricated through top-down strategy using bulk wood as raw materials. The obtained hybrid laminates demonstrate low anisotropic mechanical factor of 1.14, which was only one-eighth of the corresponding value of natural wood (8.07). Besides, such wood laminates exhibit moderate light permeability (35% of transmittance), which could provide with softening of glare and uniform illumination, thereby reducing the power consumption. Also, the remaining wood cellulose and incorporated inorganic microspheres in our laminates backscatter solar radiation and emit thermal, resulting in continuous cooling with a dT of 12 °C under one solar intensity irradiation. Combined with excellent water stability and self-cleaning property, our laminates are expected to be used as the building blocks for the construction of energy-efficient buildings with low carbon emission.

Stabilization/solidification of sand-washing slurry used for porous cold-bonded ceramsite

Solid waste is considered a promising resource to manufacture environment-friendly building materials. A huge amount of sand-washing slurry is generally generated from construction sites and plants, and its improper accumulation can pose a major threat to the ecology and the environment. To reuse this sand-washing slurry, a porous cold-bonded ceramsite was prepared using a foaming agent based on crushing technology. The influences of the sand-washing slurry content and the foaming agent content on the engineering properties of ceramsite were investigated. The microstructure of ceramsite was analyzed by scanning electron microscopy, and its crystal structure was revealed by X-ray diffraction. In addition, the inner structure of ceramsite was explored by X-ray computed tomography. The sample with a sand-washing slurry content of 70% and a foaming agent content of 15% exhibited the lowest strength, indicating that the sample with higher water absorption capacity and porosity had lower compressive strength. As an excessive amount of sand-washing slurry could decrease the mechanical properties of ceramsite, a proper mixing proportion is required to produce ceramsite. These results suggest that there is potential in using sand-washing slurry to develop a porous structure light-weight aggregate. This ceramsite could potentially be applied in landscaping and agriculture.

Influence of Non-Constant Hygrothermal Parameters on Heat and Moisture Transfer in Rammed Earth Walls

As environment-friendly building materials, earth materials are attracting significant attention because of their favorable hygrothermal properties. In this study, the earth materials in northwest Sichuan were tested and curves of thermal conductivity and water vapor permeability with relative humidity were obtained. The function curves and constants of the two coefficients were substituted into the verified nonstationary model of heat and moisture transfer in rammed earth walls and indoor air for calculation. The difference in the calculation results when the hygrothermal parameters are functions and constants were analyzed, and the influence of the non-constant hygrothermal parameters on the heat and moisture transfer in rammed earth walls, was obtained. The test results show that thermal conductivity is linearly related to moisture content, and water vapor permeability has a small variation in the relative humidity range of 0–60% and increases exponentially above 60%. The calculation results indicate that the non-constant hygrothermal parameters have little influence on the internal surface temperature of the rammed earth walls and Mianyang City’s indoor air temperature and humidity during the summer and winter. The heat transfer on the internal surface will be underestimated by using a non-constant for the hygrothermal parameter when the moisture content of the wall is low, and vice versa. In hot-humid areas or seasons with large differences in temperature and humidity between indoors and outdoors, non-constant hygrothermal parameters have a more obvious effect on heat transfer on the internal surface of the wall. The results of this study demonstrate the necessity of parameter testing.

LCIA Parameters and the Role of BIM towards Sustainability: Regional and Temporal Trends

Building materials with a low environmental impact are critical to the sustainability of the built environment. The environmental impact of materials can be determined by a Life Cycle Impact Assessment (LCIA), which constitutes multiple parameters such as the water used in a material’s life cycle. To use the LCIA approach for building material selection, its parameters need to be assigned different weights, which is the primary objective of this study. Building Information Modelling (BIM) can play an influential role when using LCIA during the building design process. With this consideration, we study the attention given to environmental sustainability in buildings and the responsiveness of BIM in this case. A multi-regional survey of 120 experts from academia and industry was conducted. The results show the relative importance of LCIA parameters and the focus of the building sector on environmental sustainability. The current and the future responsiveness of BIM towards environmental sustainability is also indicated. To promote the integration of LCIA in building design and performance assessment, the future role of BIM applications is explored. The results will contribute to research and practice in the sustainable built environment by helping select environment-friendly building materials.

Use of a Full Factorial Design to Study the Relationship between Water Absorption and Porosity of GP and BW Mortar Activated

The alkali‐activated materials prepared by activation of glass powder (GP) and brick waste (BW) on the porosity and absorption of geopolymer paste by alkaline solution (alkali + water glass) were investigated. The effect of the combination of GP and BW on the porosity and absorption of the prepared geopolymer paste was monitored and evaluated by both laboratory and analytical methods. In this paper, three mortars were made with two sources of geopolymer containing 100% BW and 100% GP and blended with 90% GP and 10% BW replacements by mass. The compressive strength, porosity, and absorption of alkali‐activated mortar were concurrently examined. Furthermore, the laboratory results obtained were estimated by the general full factorial design method. Finally, the analysis of variance was performed using the test results to analyze the importance of the effect factors and their interactions on the selected responses. The results concluded that mortar activated combined with 10% BW and 90% GP could be utilized in the industry of construction with minimum pollution problems and environment‐friendly building materials, with the effect variables significantly affecting the responses.

Recycling of rice husks ash for the preparation of resistant, lightweight and environment-friendly fired bricks

Rice husks ash was previously shown as a raw material for the foamed silicates production. This article is devoted to the use of the foamed silicates as an aggregate for the manufacture of lightweight cellular clay bricks. The coalescence of the foamed silicate structure inside a ceramic matrix leads to obtaining cellular lightweight ceramics in the process of firing. The present study has shown that on decreasing the ceramic brick density while using the foamed silicate filler the mechanical strength is not significantly decreased as opposed to the bricks with inert fillers. This effect is explained by obtaining a high strength glass layer on the inside surface of the cells. The lightweight cellular bricks demonstrate good heat insulation properties. Using rice husks ash as a raw for foamed granulated silicates in the manufacture of lightweight ceramic bricks not only solves the problem of rice husks as a large-tonnage waste, but also provides an environment-friendly building material with strength and heat insulation.

Integration of Emergy Analysis with Building Information Modeling

Traditional energy analysis in Building Information Modeling (BIM) only accounts for the energy requirements of building operations during a portion of the occupancy phase of the building’s life cycle and as such is unable to quantify the true impact of buildings on the environment. Specifically, the typical energy analysis in BIM does not account for the energy associated with resource formation, recycling, and demolition. Therefore, a comprehensive method is required to analyze the true environmental impact of buildings. Emergy analysis can offer a holistic approach to account for the environmental cost of activities involved in building construction and operation in all its life cycle phases from resource formation to demolition. As such, the integration of emergy analysis with BIM can result in the development of a holistic sustainability performance tool. Therefore, this study aimed at developing a comprehensive framework for the integration of emergy analysis with existing Building Information Modeling tools. The proposed framework was validated using a case study involving a test building element of 8’ × 8’ composite wall. The case study demonstrated the successful integration of emergy analysis with Revit®2021 using the inbuilt features of Revit and external tools such as MS Excel. The framework developed in this study will help in accurately determining the environmental cost of the buildings, which will help in selecting environment-friendly building materials and systems. In addition, the integration of emergy into BIM will allow a comparison of various built environment alternatives enabling designers to make sustainable decisions during the design phase.

Properties of environmental concrete that contains crushed walnut shell as partial replacement for aggregates

Concrete production consumes a large amount of fine and coarse aggregates. Therefore, eliminating or reducing the consumption of aggregates in concrete can produce environment-friendly building materials. Considerable research has confirmed that the use of waste materials in concrete addresses the high utilisation of raw materials. Walnut is a common farming product in the north of Iraq. A substantial amount of walnut shells is disposed of in landfills. In the present work, crushed walnut shells (CWS) were selected as partial substitute for coarse and fine aggregates at ratios of 5 to 25% with an increment of 5%. The experimental work was divided into three parts. Firstly, fine aggregates were replaced with CWS at the preceding ratios. Secondly, coarse aggregates were substituted with CWS at the aforementioned ratios. Thirdly, fine and coarse aggregates were replaced by CWS at the same proportions. Absorption ratio, compressive strength, flexural strength, splitting strength and dry density were determined at 28 days for all the mixtures and the control sample. Results showed that all tested properties, except absorption ratio, decreased when CWS was used. Optimal results were achieved when fine and coarse aggregates were replaced together with CWS. Advantageous values were obtained with a 15% CWS replacement for both types of aggregates.

Structural Health Monitoring of Timber Using Electromechanical Impedance (EMI) Technique

Nowadays, the electromechanical impedance method has been widely used in the field of structural healthy monitoring, especially for the concrete and steel materials. However, the electromechanical impedance studies on damage detection for timber are limited due to the anisotropic and ununiform biomaterial properties. As a low‐cost and environment‐friendly building material, timber has been widely used in the construction. Thus, it is beneficial to develop electromechanical impedance technique for structural healthy monitoring of timber so as to ensure the stability and safety of the entire timber structures. In this paper, two damage factors, i.e., the damage location factor and the damage size factor of timber specimens are investigated by using the electromechanical impedance method. The method is implemented by using a patch of Lead Zirconate Titanate transducer both as an actuator to generate stress waves and a sensor to detect stress waves after propagating across the timber specimens. Then, the damage index‐root mean square deviation is employed to evaluate the damage severity of the timber specimens. The results indicate that the damage index changes consistently with the change of damage location and size factors, and the proposed method using electromechanical impedance technique can efficiently estimate the damage and its severity.

Biostimulation of calcite precipitation process by bacterial community in improving cement stabilized rammed earth as sustainable material.

Rammed earth has been enjoying a renaissance as sustainable construction material with cement stabilized rammed earth (CSRE). At the same time, it is important to convert CSRE to be a stronger, durable, and environment-friendly building material. Bacterial application is established to improve cementitious materials; however, bioaugmentation is not widely acceptable by engineering communities. Hence, the present study is an attempt applying biostimulation approach to develop CSRE as sustainable construction material. Results showed that biostimulation improved the compressive strength of CSRE by 29.6% and resulted in 27.7% lower water absorption compared to control. The process leading to biocementation in improving CSRE was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscope-energydispersive spectrometer. Further, Illumina MiSeq sequencing was used to investigate changes in bacterial community structures after biostimulation that identified majority of ureolytic bacteria dominated by phylum Firmicutes and genus Sporosarcina playing role in biocementation. The results open a way applying biological principle that will be acceptable to a wide range of civil engineers.

Recycled Aggregate filled waste plastic bottles as a replacement of bricks

Abstract Concrete is and has been the basic building material for most of the infrastructure for last few decades. However, the aging infrastructure is resulting in millions of tonnes of construction and demolition waste, mainly aggregates. Used plastic bottles are also a significant waste management concern of the rapidly urbanizing society. The current work is aimed at combining these two waste products and generating an alternative for conventional bricks, thus yielding a sustainable and environment-friendly building material. Used plastic bottles were filled with crushed recycled aggregate (RA) and desired water content and were sealed. Bottles containing crushed RA with size less than 425 µm had higher compressive strength as compared to those containing RA with a size between 425 µm & 4.75 mm. Also, 5% water content was found to be the most optimal in terms of compressive strength. Exposure to 3.5% saline solution for 28 days did not affect the compressive strength of such bottles significantly. Such waste material filled plastic bottles are not only cheap, zero-energy, and emission-less; they also obviate the necessity of disposal of the bottles and the waste materials. Such environment-friendly and low-cost building materials are expected to pave way for low-cost housing in economically-deprived sections of the world.

Experimental Study on the Effects of Calcium-rich Materials on the Early Compressive Strength of Completely Decomposed Granite (CDG) Base-geopolymer

Geopolymer is a kind of environment-friendly building material that is currently used to substitute for the position of Portland cement. As a new type of construction material, the main reaction product of geopolymer is a three-dimensional reticular structure N-A-S-H gel. It initiates the polymerization reaction to produce N-A-S-H and C-S-H gels and forms a new geopolymer material after the addition of calcium-rich materials. In the current stage of research, the cementitious materials for the traditional geopolymer are mostly metakaolin and fly ash. Completely Decomposed Granite (CDG) has been used as the main cementitious material for the preparation of geopolymer, and the effect of calcium-rich materials on the early mechanical property of geopolymer has been studied in this research (paper).

Structural Condition Evaluation of an In-Service Glued-Laminated Timber Bridge Based on the Dynamic and Static Testing

The structural use of wood has increased steadily in recent times, including a renewed interest in the use of timber as a bridge material. As the only environment-friendly and resource-saving building material, wood has been gradually uesd for short and medium span bridges in China. In 2014, The domestic largest single-span glued-laminated timber (glulam) deck arch bridge crossing a freeway was completed and put into operation in Zhangjiajie City, central China' Hunan province. In order to know the bearing capacity of superstructures and assess its working conditions, in-site static and dynamic testings has been carried out. Many measures including finite element simulation, field test and comparision between test results and calculated results have been employed to study responses of the bridge under static loads and dynamic loads as well. The researches indicate this glulam footbridge has performed well in service and appear to be cost effective when compared with the cost of installing traditional concrete and steel bridges.

Impact of polyethylene glycol on porosity and microstructure of sand-lime product

Autoclaved sand-lime products are environment-friendly building materials in the form of bricks and blocks. Due to great interest in silicate products, there have been numerous studies and modifications aimed at improving the properties of the material. The article presents the most important characteristics of sand-lime products, both traditional as well as modified with polyethylene glycol. The purpose of described research was to estimate porosity (determine the type, size and pores distribution) and to analyze the microstructure of aforementioned samples. From the practical point of view, these characteristics are particularly important in the construction materials. The following tests have been carried out: bulk density using the hydrostatic method, capillarity, water absorption and mercury porosimetry of samples containing polyethylene glycol. The samples were also subjected to observation of the microstructure under the scanning electron microscope. Preliminary research findings clearly show the positive influence of the used substrate on the basic properties of modified sand-lime product. In comparison to the reference sample, modified products showed a decrease in water absorption and reduced capillarity. The confrontation of the measurements made using a mercury porosimeter with observation of the microstructure, showed differences in the distribution of pores and their size. Besides the additive, the production process itself has a huge impact on the properties of silicates (mixing process, time and temperature of autoclaving).

Energy Efficient and Environment-Friendly Building Materials for Cost-Effective Urban Housing

In order to fulfil the demand of urban population with sustainable development and use of local material for construction purpose which is cost effective and easily available in local so that the exponential population growth and the existing housing shortage have made the situation even more alarming. To develop the mechanism and large scale filed application of proven innovative and emerging building materials and technologies in the construction sector which is available in local area. The sustainability aspects of building construction need to be factored in for industrial housing construction. This building system was evolved and perfected to reduce the waste, save energy, save water, and create a pollution free environment with smart construction methodology.

Strength and Ultrasonic Characteristics of Alkali-Activated Fly Ash-Slag Geopolymer Concrete after Exposure to Elevated Temperatures

AbstractGeopolymer concrete is an environment-friendly building material which has attracted increasing interest in many fields as a replacement for conventional concrete. The main objective of this paper is to study the residual behaviors of the alkali-activated fly ash–slag geopolymer concrete (FSGC) under different heating temperatures and cooling regimes. Changes in weight, compressive strength and ultrasonic pulse velocity were firstly investigated. Then the wavelet packet technique was adopted to further analyze the measured ultrasonic signals in frequency domain. Finally, the microstructures were investigated by scanning electron microscopy. The results indicate that an increase in temperature makes the weight, compressive strength, and ultrasonic pulse velocity value of FSGC decrease, especially under extreme heat conditions. The deterioration of specimens cooled by watering is more obvious than that of specimens cooled naturally. Based on the experimental results, it can be concluded that the crit...

The Application of Energy-Saving and Environment-Friendly Decorative Materials in Architectural Decoration Construction

the living environment of people increasingly demanding, architectural decoration only simple demined formal beauty from the past and nowadays gradually develop into a comprehensive discipline, including energy-saving, environment protection and beauty. This paper is starting from the perspective of the development of building energy conservation, and is to make architectural decoration construction environment as a starting point to explore the application and development of environment-friendly building materials and energy-saving. And in the end it makes the prospect of building decoration materials.

A Study on Environmental Load Assessment of Early Strength Activator Blast Furnace Slag

Development of environment-friendly building materials has recently been increasing with the use of industrial waste and by-products, but concrete containing blast furnace slag (BFS) is excellent in terms of environmental load and shows relatively insufficient early strength. Development of by-products to supplement this insufficiency is deemed necessary. Therefore in this study, an early strength activator blast furnace slag (A-BFS) was developed and environment performance of the developed A-BFS was assessed to assess environmental load (CO2). As a result, early strength was developed in mortar specimen mixed with A-BFS. When environmental load (CO2) was assessed on the mortar specimen, life cycle CO2 emission from production of 1kg of A-BFS was found to be 0.057kg-CO2/kg.

Study on the characteristics of pollutant emission from floor adhesive formulated using red clay

Development of building materials has been actively underway using natural materials in order to improve indoor air quality. Among such natural materials, red clay has been frequently used for development of building materials. In this study, 138 different environment-friendly adhesives were analyzed, aiming at determining the performance of adhesives prepared using red clay. The emission factors of formaldehyde and total volatile organic compounds (TVOCs) were examined for adhesives that had acquired the environment-friendly building materials certification before comparing with the characteristics of emission from red clay containing adhesives. In order to analyze pollutant reduction performance of the red clay adhesive, we exposed the clays to pollutants of formaldehyde and volatile organic compounds (VOCs), and analyzed the emission reduction performance due to adsorption on the red clay. The analysis results demonstrated the emission reduction performance of formaldehyde. Lastly, we compared the pollutant emission factors from multilayer building materials using red clay adhesive and general materials. The comparison results showed low emission factors for formaldehyde and VOCs. These results can be used as the basic data on performance characteristics of red clay adhesive.

Fracture Toughness of Northeast China Larch

Wood, as a green and environment-friendly building material, is widely used in building engineering. Naturally grown, wood has various defects like knots, cracks and inclined grain. Fracture Mechanics is thus an efficient tool to investigate the mechanical behavior of wood and wood-based composite products. According to Linear-elastic Fracture Mechanics (LEFM), fracture toughness can be introduced to measure the resistance to crack propagation. Crack was assumed to occur when the stress intensity factorKreached a critical valueKC.Fracture in wood usually involves not only the Mode I type (open) fracture, but also the Mode II type (shear) fracture. For getting a better understanding of the crack growth phenomenon of Northeast China Larch, it is, therefore, essential to assess theKICandKIIC, which are the critical stress intensity factors for Mode I and Mode II type fracture, respectively. In the current study,KICandKIIC, of Northeast China Larch were determined through tests with compact tension specimens and tests with compact symmetric shear specimens, respectively. In addition, the material properties tests were also performed. All of the specimens were cut from the same batch of Glulam beams. Based on the obtained data from experiments, LEFM was employed to explain the fracture failure in the form of crack propagation. Using Extended Finite Element Method (XFEM), simulation of the crack propagation in Mode I and Mode II was performed incorporating ABAQUS. The crack propagation and the load-displacement curves of numerical simulation were in good agreement with experiments, which validated that the proposed numerical approach is suitable for analysis of crack growth in the specimens. As part of a larger program to investigate the fracture behavior of Glulam beams made of Northeast China Larch, this study provides the material properties and validation of the numerical simulation approach. A series of experiments of full-size curved Glulam beams subject to bending and the corresponding simulations extending the numerical approach of this study to the cases of full-size wood composite members are under development.