Building Materials In China Research Articles

Establishment of an Environmental Impact Factor Database for Building Materials to Support Building Life Cycle Assessments in China

The construction industry increasingly poses significant threats on the environment, highlighting the importance of developing life cycle assessments (LCAs). Research on building LCA databases has been carried out in many countries. However, in China, the absence of public data for environmental impact assessments poses significant challenges for building life cycle assessments (LCA). Therefore, this study aims to facilitate the life cycle assessment of buildings in China by comparing and analyzing databases from South Korea and the European Union. The goal is to establish a unit-based environmental impact database for Chinese building materials. Three environmental impact factors of ten major building materials in these three databases were compared and a basis for the inter-application of the databases was established. Based on the combination of the analysis results, the supplementation of the environmental impact factor database of building materials in China was proposed. In addition, a case study using a quantity take-off (QTO) for an actual building in China was performed to review the plan’s applicability.

The integration of BIM in the application of green building materials in construction projects

In recent years, with the growing call for sustainable development, green building materials, which are of great meaning for reducing resource and environmental impacts, have attracted more and more attention. However, in China, a country with frequent construction activities and high resource consumption, the application of green building materials in construction projects still faces challenges. Building Information Modelling (BIM) as an emerging technology in the construction industry can increase the adoption rate of green building materials in construction projects. The aim of this study is to identify the barriers encountered in the application of green building materials in Chinese construction projects, and to propose corresponding improvement measures by integrating BIM in the decision making. This study adapted a qualitative research method, using semi-structured interviews as a research tool. A total of 6 respondents (including project managers, architects, engineers, and researchers) from Chinese construction companies and research institutions collected interview data, and used Nvivo software to analyze and summarize. The results of this study show that although the application of green building materials in construction projects in China still faces challenges, including market acceptance and supply chain issues, cost and economic feasibility issues, and lack of relevant technology and knowledge. In addition, the study found that BIM technology made a great contribution in promoting the application of green building materials. Through BIM technology, the whole life cycle information management such as material selection, engineering simulation and performance evaluation of construction projects can be carried out, so as to improve the application of green building materials. By exploring the obstacles to the application of green building materials in China’s construction projects and combining with the promotion of BIM technology, this study puts forward a series of specific suggestions and solutions to foster the application of green building materials. This research has made certain theoretical and practical contributions to foster the application of green building materials for the sustainable development of China's construction industry.

Carbon emissions from accumulated stock of building materials in China

The stock of building materials has critical impact on sustainable development and on the reduction of the carbon emissions of the construction industry; however, the accumulated stock of building materials and its carbon emissions remain uncertain. To clarify the stock situation regarding existing buildings in China and provide reference material to support reduction of building–related carbon emissions, the accumulated building material stock and associated carbon emissions were visualized and quantified in this study based on building vector data of 33 cities and nighttime light data. In 2017, 8.8 Gt of building materials in 161.1 billion m3 of accumulated building stock produced emissions of 17.8 Gt CO2eq. Concrete and cement represented the main material types and the greatest sources of emissions. Notable disparities were found in material stock among different regions, determined primarily by factors such as areas of urban and rural construction land, population, GDP, and landform. Spatial visualization of material carbon emission intensity in China revealed a pattern of “higher in the southeast, lower in the north and midland,” and showed three aggregation modes. The results of this study could serve as scientific reference for new policies regarding low–carbon building, thereby promoting carbon emission reduction and sustainable utilization of resources in the construction industry.

Carbon Emissions from Accumulated Stock of Building Materials in China

Carbon Emissions from Accumulated Stock of Building Materials in China

Simultaneous removal of phosphorus and organic contaminants from phosphogypsum using hydrothermal method for gypsum resource regeneration

Phosphogypsum (PG) is a common chemical by-product from wet process phosphoric acid production, accumulated stockpiles of 300 million tons in China. The challenge for the comprehensive utilization of PG is thorough removal of phosphorus and organic contaminants from PG, which inevitably entails the loss of overall whiteness and limits its utilization in building materials and other fields. This work investigated the speciation of phosphorus and organic contaminants in PG by FTIR spectroscopy, Raman spectroscopy, XRD, SEM-EDS and GC-MS. On this basis, by using K2S2O8 as a mineralizer, PG was transformed into anhydrous calcium sulfate powder and the organic contaminants were fully decomposed (removal rate >80%, with residual TOC of 0.078%) under hydrothermal treatment. Under optimal hydrothermal conditions (0.3 M K2S2O8, heated at 120 °C for 12 h), the whiteness of product significantly improved from 40.9 to 97 and effective removal of phosphorus was achieved (more than 76%). The residual phosphorus in treated PG was 0.108%, which met the standard of PG as a building material in China GB/T-23456 2018 (P content < 0.2%). The mechanism study revealed that the phase transformation of calcium sulfate from dihydrate to anhydrous played a dominant role in the removal of phosphorus, H+ and SO42- from K2S2O8 decomposition facilitated the dissolution-recrystallization process of calcium sulfate, allowing the phosphorus in the lattice to escape. In addition, by thermal activation, K2S2O8 generated free radicals of SO4•- and OH• dissipated the organic contaminants in PG. This work provides theoretical and practical bases for the harmless disposal and resource recycling of industrial by-product gypsum, and it is of great significance to build the "zero-waste city".

Life cycle assessment of embodied human health effects of building materials in China

With the rapid development of the construction industry in China, a large number of building materials have been consumed and resulted in huge pressure to the resources and environment. Based on localized construction material inventory data, China-specific characterization factors in LIME-3 (Life Cycle Impact Assessment based on Endpoint Modeling) was used to evaluate the environmental impact of human health. It is found that ceramic tiles and steel have high burden of human health impact, which are 2.98E-05 DALY and 1.72E-05 DALY, respectively, while gravel and natural sand have relatively low impact, which are 5.12E-08 DALY and 4.30E-09 DALY, respectively. Among the five midpoint impact categories (climate change, air pollution, photochemical oxidant formation, water consumption and human toxicity) that have effects on “human health”, the contribution proportion of different building materials vary significantly. The environmental impact assessment results of different building materials on “human health” under LIME-3 and ReCiPe were compared. Results show that the burden of human health impact for ceramic tile under LIME-3 is nearly 67 times that under ReCiPe, which is mainly due to the different proportion of human toxicity in the endpoint of human health and the difference between the two methods in material characterization factors. For high impact burden materials such as steel and ceramic tiles, impact mitigation strategies have been proposed, such as applying electric arc furnace steel making to improve the productivity of steel and the recycling rate of scrap steel, and promoting new dry powder production processes to reduce alkanes and fluorides emission. This study considered an additional midpoint impact category (human toxicity) based on the LIME-3, directing the impact assessment against indicators located at the end of the impact pathway, such as human health. A database of characterization factors of human toxicity for dozens of substances or components has been constructed. Efforts were made in the direction of developing the application of the most widely used impact assessment methods.

REUSING “XIA BO” KILN FURNITURE WASTE FROM THE CERAMIC INDUSTRY AS A BUILDING MATERIAL AND ANALYZING ITS EFFECT ON THE INDOOR THERMAL ENVIRONMENT

ABSTRACT “Xia Bo” is a type of kiln furniture for ceramic production that becomes solid waste after damage during the firing process. However, it has traditionally been reused as a building material in China’s kiln-producing areas. With technological changes in kilns in recent years, Xia Bo is no longer necessary as kiln furniture for firing ceramics. However, as a low-tech and ecologically friendly construction material, it is overlooked as a suitable material. Traditional Xia Bo wall buildings are increasingly being left unused or even destroyed. This study examined the town of Pengcheng in the Cizhou kiln cultural heritage area. The main features and shapes of Xia Bo used in existing buildings were analyzed, and the typical application mode and construction technology for the “horizontal placement method” and the “vertical placement method” of the Xia Bo used in building walls were summarized. The thermal insulation performance of different types of Xia Bo wall was also examined, especially their thermal performance was compared with that of traditional brick wall buildings in indoor thermal environments. This study emphasizes and recognizes the ecological and economic value of reusing ceramic industrial waste as building materials to ensure that this technology can be protected and adopted in contemporary architecture.

Embodied energy and carbon emissions of building materials in China

Increasing building constructions have become one of the fastest-growing drivers of carbon emissions. Energy conservation and carbon reduction in buildings have become increasingly crucial in the context of global carbon neutrality. This paper assesses the annual total energy and carbon embodied in the ten most intensively used building materials in China, aiming to find potential CO2 reduction opportunities in the construction industry from a macroscopic perspective. The results show that: (1) the embodied energy and carbon of cement, steel, and brick account for more than 70% of the total embodied energy and carbon of all building materials; (2) differences in the embodied energy and carbon between steel-concrete buildings and brick-concrete buildings are not distinct; (3) disparities in the embodied energy and carbon of building materials between different regions are significant. The eastern and south-eastern regions consume excessive building materials and embody significantly higher energy and carbon than other regions. Several strategies are provided for China's building sector in energy and carbon reduction.

Thermal cotreatment of municipal solid waste incineration fly ash with sewage sludge: Phases transformation, kinetics and fusion characteristics, and heavy metals solidification

Thermal treatment is an effective method to detoxicate municipal solid waste incineration (MSWI) fly ash (FA) and then produce secondary materials for recycling, but the development of this method is limited by the high energy cost. In this study, two typical types of FA are proposed to be thermally cotreated with sewage sludge (SS), respectively, to reduce energy consumption and control the risk of heavy metals leaching. The SiO2 and Al2O3 with high content in SS were prone to react with compounds (e.g., Na2O, MgO, and CaO) in FA to form low-melting-temperature eutectics, such as NaAlSi3O8 and CaMgSi2O6, greatly reducing the ash fusion temperatures (AFT) by up to 182 °C. Mixtures with 45 wt% FA showed the greatest reduction on AFT compared to mixtures with 15 and 30 wt% FA. Also, the kinetics analysis based on TG/DSC results in conjunction with Avrami–Erofeev model showed that the apparent activation energy of mixtures of FA and SS (i.e., 561.4 ± 110.6 kJ/mol) was obviously lower than that of FA (i.e., 660.0 ± 12.9 kJ/mol). Thermal cotreatment of FA with SS significantly increased the removal efficiency of chlorine from 23.5 to 66.52 wt% to 80.5–98.2 wt% by facilitating the reactions releasing HCl, which is beneficial for utilizing the generated products as construction materials. Heavy metals in the solid residues from thermal cotreatment of FA and SS were effectively solidified via ion exchange into Ca-bearing minerals or aluminosilicates, and the leaching concentrations of Cd, Cr, Cu, Ni, Pd, and Zn mostly well met the standards for utilization as construction and building materials in China.

Ecological Assessment of Clay Brick Manufacturing in China Using Emergy Analysis

Clay brick is a commonly used building material in China. Due to the enormous land destruction and excessive consumption of resources, such as materials and energy in the manufacture of clay brick, it is important to study its overall sustainability, i.e., in terms of impact on the environment, services, and economy. In this study, emergy analysis is employed, which offers a holistic perspective, unlike typical environmental studies. A series of emergy indices such as renewability rate (R%), nonrenewability rate (N%), unit emergy values (UEVs), emergy yield ratio (EYR), environmental loading ratio (ELR), and emergy sustainability index (ESI) were used to study manufacturing of clay brick. In addition to calculating UEVs of clay brick manufacturing in China (7.18 × 1012 sej/kg), our detailed analysis shows that the nonrenewable resources and imported energy have a dominant impact on the emergy contribution (50.6%) and within the nonrenewable resources, clay is the foremost item, accounting for 33.5% of local emergy inputs. Given different electricity UEVs, the change ranges of clay brick system UEVs are 14.9% (scenario 1), 7.24% (scenario 2), 8.91% (scenario 3), and 6.94% (scenario 4). Furthermore, several policy suggestions are discussed for improving the sustainability of the evaluated system, involving the energy structure adjustment, recycling material replacement, and promotion of energy-saving systems.

Weathering mechanism of red discolorations on Limestone object: a case study from Lingyan Temple, Jinan, Shandong Province, China

Red discolorations are an effloresce phenomenon detect on the surface of stone objects and considered as damage factor in both esthetic and conservation points of view. It is very difficult to remove and seldom report about their weathering mechanism. Recently, numerous of red discolorations have affected the limestone objects of Lingyan Temple in Shandong province, one of the most important building materials in China. In order to set up the appropriate conservation remedy, it is essential to identify the origin, characteristics, composition, and the formation process of red discolorations. Several analytical and investigation techniques, such as X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), Micro-Raman spectroscopy (Raman), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS) were used to better understand the red discolorations. The results demonstrated that the discolorations on limestone surface have been caused by carbonic acid weathering process. The red discolorations consisted mainly of kutnohorite (Ca(Fe,Mg,Mn)CO3) and iron oxides. They showed tabular, lamellar, and granular morphologies, which originated from the in situ carbonic acid weathering of kutnohorite. After rainfall, the Ca, Mg, Mn ions with relatively high solubility were primarily leached from carbonatite phases. It was resulting in the sedimentation of red iron oxides through a chemical reaction and physical adhesion. Based on those analyses, a chelating agent (ethylenediamine tetraacetic acid disodium salt) was chosen to remove theses red discolorations on the stone object.

The Benefits and Barriers for Promoting Bamboo as a Green Building Material in China—An Integrative Analysis

Bamboo is commonly considered as a green, environmentally friendly material. However, it appears that bamboo finds limited application in the form of green building materials in the Chinese construction sector. In order to explain this phenomenon and promote the material’s application, this study summarizes the benefits of applying bamboo materials and presents an analysis on barriers affecting the effective application of bamboo materials in this specific building sector. Research data are collected from both literature surveys and semi-structured interviews with a group of carefully selected experts from the Chinese building sector. Fifteen characteristic barriers are identified, such as ineffective action by government departments. An integrative analysis is conducted, including investigation on the hierarchy structure among characteristic barriers using the interpretive structural modeling (ISM) method and the classification of barriers from a driving-driven perspective using the Cross-impact Matrix Multiplication Applied to Classification (MICMAC) technique. This classification provides a different profile for the characteristic barriers from that of traditional barrier analysis methods. The findings provide valuable references for helping policy makers and practitioners adopt effective policies and measures to promote the application of bamboo for green materials in building sector.

The classification and selection of indoor shade-tolerant plants of indoor chemical pollution

It has been an urgent issue of finding a reasonable and safety methods to control the indoor benzene pollution form building materials in China. Twenty two common indoor shade-tolerant plants were tested by artificial closed fumigation to investigate their sensitivity on high concentration formaldehyde and benzene. And then sensitivity of each plant was classified according to the degree of symptoms. The results indicate that Impatiens balsamina, Begonia × aelatior and Melissa officinalis are sensitive to indoor formaldehyde and benzene pollution.

Strategic Research on Nonmetallic Mineral Resources for Building Materials in China

Strategic Research on Nonmetallic Mineral Resources for Building Materials in China

Study on applying inorganic polymers to restore rammed earth brick monuments

Rammed earth has been used as a building material in China for thousands of years. However, due to weather and environmental impacts, monuments built from rammed earth suffer from varying degrees of damage. To restore these structures effectively, the authors heated kaolinite featuring the same characteristics of rammed earth and added glass powder and sodium hydroxide to make inorganic polymers. Subsequently, using various mix ratios, calcination temperatures and calcination times, the compressive strength of the clay produced was investigated. It was determined that by controlling the inorganic polymers and clay ratio at 1:1 and calcinating the mixture at 300°C for 1 h, the compressive strength could be increased to 430·9 kg-force/cm2. This result met the Chinese national standards for red bricks, and the proposed material consumed only 1% of the energy used during the red brick burning process. The proposed method substantially reduced carbon dioxide (CO2) emissions while conserving energy. These results verify that inorganic polymers can be applied to rammed earth used to restore monuments.

Research on the Application of Green Building Materials in China

With the developing demand for living environment and increasing emphasis on the development of a green economy in China, using green building materials has gradually become a new opportunity for the development of our country’s construction industry. This article mainly makes an introduction about the concept, advantages of the GBM(Green Building materials), and some different types that are currently used in China, so as to have a more comprehensive and overall understanding of this kind of materials. In addition, we also elaborate on the problems in the use of GBM in this paper, and finally come up with some corresponding suggestions. We hope that through this short article, relevant researchers will have more understandings of the application of GBM, and we also hope that some references can be useful for the progress of sustainable development in the construction industry of China.

Research progress of wheat straw and rice straw cement-based building materials in China

This paper comprehensively describes the development process, existing problems and future solutions of wheat straw and rice straw cement-based building materials in China. Straw cement-based building materials are environmentally friendly and have excellent thermal insulation, impact resistance, as well as social and economic benefits. In this paper, straw cement-based building materials are divided into mechanical and composite-type building materials; previously, composite-type materials have mainly been studied. As the percentage of straw increases, the compressive strength of these materials decreases; therefore, composite-type building materials with a straw content of no greater than 5% can be used for non-load-bearing structures. These materials have problems such as difficulty in stirring and slow hardening during preparation. Modification treatments can improve the compressive strength and flexural strength, but these processes often result in energy consumption and environmental pollution. For the two types of straw building materials, additional research is needed to determine the relationship between the mechanical properties and the microstructure and failure mechanism. A new concept of a mechanical bionic straw material is proposed that can overcome the above problems, suggesting the possible development of a new type of bionic light straw building material.

Progress of research into cotton straw and corn straw cement-based building materials in China

This paper reviews the development of cotton straw and corn straw cement-based materials in China. With the use of unmodified straw fibres, the compressive strength of the cement-based material decreases with an increase in corn and cotton straw content, but the rate of decrease is considerably lower than that of wheat and rice straw, mainly because of differences in the strength of the straw. The incorporation of fly ash, urea formaldehyde resin and other materials can effectively improve the mechanical and thermal insulation properties of mixed-type building materials. Three methods of modification are proposed – alkali treatment, grafting treatment and direct addition of a modifier. A multiple linear regression equation between mechanical properties and the content of the main components of the cotton straw cement-based materials is obtained, which provides a theoretical basis to predict and design cement-based block materials. Finally, to address the problems of the mix type (difficult stirring, slow hardening, and energy demands and environmental pollution during the modification process), the concept of a composite-type bionic straw cement-based building material is introduced, which provides direction towards the development of new bionic light straw materials.

Mechanical strength and durability performance of autoclaved lime-saline soil brick

The growing demand of building materials in China has intensified the search for a greener and more environmental friendly substitute for conventional clay brick. One of the proposed alternatives is the use of brick incorporating saline soil as replacement for conventional siliceous sand. Saline soil is available in abundance in China but because saline soil contains high content of soluble salts, it is unsuitable for agricultural use. It is therefore interesting to explore the utilization of saline soil in the production of autoclaved brick for both economic and environmental benefits. As part of research project in producing lime-saline soil bricks, this paper presents an investigation of the mechanical strength and durability properties of the bricks with varying amount of fine sand replacements (10%, 20%, 30% and 40%) for saline soil. The results revealed that in general, the lime-saline soil bricks had good water resistance in terms of softening coefficient and drying-wetting durability as no reduction in compressive strength was observed. Incorporation of fine sand, particularly at 40%, also resulted in improvement in the drying-wetting and freeze-thaw durability properties of the autoclaved lime-saline soil bricks. In addition, autoclaved lime-saline soil sample exhibited enhanced salt fixing ability compared to raw saline soil sample. Overall, it can be said that the autoclaved lime-saline soil brick exhibit good properties in terms of mechanical strength and durability performances, and further improvement can be achieved through the incorporation of up to 40% fine sand.

Evaluation of Natural Radioactivity in Marine Sand Deposits from Offshore China

Natural radioactivity is very important for the assessment of the marine sand property and usability. By using gamma spectrometry, the concentration of the natural radionuclides 226Ra, 232Th and 40K have been measured in marine sand deposits from Liaodong Bay (LDB), North Yellow Sea (NYS), Zhoushan area (ZS), Taiwan Shoal (TS) and Pearl River Mouth (PR), offshore China, which are potential marine sand mining areas. The radiation activity equivalent (Raeq), indoor gamma absorbed dose rate (DR), annual effective dose (HR), alpha index (Ia), gamma index (Ig), external radiation hazard index (Hex), internal radiation hazard index (Hin), representative level index (RLI), excess lifetime cancer risk (ELCR) and annual gonadal dose equivalent (AGDE) associated with the natural radionuclides are calculated to assess the radiation hazard of the natural radioactivity in the marine sands offshore China. From the analysis, it is found that these marine sands are safe for the constructions. The Pearson correlation coefficient reveals that the 226Ra distribution in the marine sands offshore China is controlled by the variation of the 40K concentration. Principal component analysis (PCA) yields a two-component representation of the entire data from the marine sands, wherein 98.22% of the total variance is explained. Our results provide good baseline data to expand the database of radioactivity of building materials in China and all over the world.