AVP - Education

1. Material Characterization for Sustainable Concrete Paving Blocks

Author:Wang, XY;Chin, CS;Xia, J


Abstract:Recycled aggregates have been widely studied and used in concrete products nowadays. There are still many waste materials that can be used as recycled aggregates other than crushed concrete particles. This paper aims to study the property variations of sustainable concrete paving block incorporating different contents of construction wastes. Five different types of waste materials were used in this project, including: recycled concrete coarse aggregate (RCCA), recycled concrete fine aggregate (RCFA), crushed glass (CG), crumb rubber (CB), and ground granulated blast furnace slag (GGBS). According to the test results of the properties of blocks mixed with different levels of wastes materials, it is concluded that adding both RCCA and RCFA in the block can decrease its strength and increase the water absorption. The suggested replacement levels for RCCA and RCFA are 60%% and 20%%, respectively. Mixing crushed glass in the concrete paving blocks as a type of coarse aggregates can improve the blocks' strength and decrease the blocks' water absorption. Addition of crumb rubber causes a significant deterioration of blocks' properties except for its slip resistance.
2. Preface

Author:Chin, Chee

Source:Sustainable Buildings and Structures - Proceedings of the 1st International Conference on Sustainable Buildings and Structures, ICSBS 2015,2016,Vol.

3. A Corpus-Based Functional Analysis of Complex Nominal Groups in Written Business Discourse: The Case of "Business"

Author:Ruan, ZL


Abstract:This paper uses a case study approach to explore the internal structure of complex nominal groups in written business discourse. A one-million word corpus of banks' corporate annual reports was compiled, and complex nominal groups with business as head noun were analyzed in terms of functions and logical relationships. The analysis shows that in the business English texts, complex nominal groups have distinctive functional and logical structures as well as particular patterns of co-occurrences among multiple premodification. Classification was found to be the main function of the experiential structure, with sub-modification used for further specifying the head referent. The co-occurrences of premodifiers also show the tendencies of functional associations underlying the configuration of the experiential structure. These findings suggest the distinctive register features of the informational writing in the written business discourse. The paper concludes with pedagogical implications of the findings for the teaching of business English to language learners.
4. Metacognitive awareness of EFL student writers in a Chinese ELT context

Author:Ruan, ZL


Abstract:This paper reports on an investigation into metacognitive awareness of Chinese English as a foreign language (EFL) student writers, under a threefold metacognition framework - person, task, and strategy variables, and within the broader domain of cognitive writing theories. Data were collected in a Chinese tertiary English language teaching (ELT) context through small-group interviews with 51 English-major students prior to an English writing course. Findings show that motivation, self-efficacy, and writing anxiety constitute students' awareness of person variables influencing their EFL writing, whereas their task awareness involves task purposes, task constraints, and cross-language task interference. Strategy awareness of planning, text generating, and revising was found typical of novice EFL student writers. The paper proposes an interactional model of EFL student writers' metacognitive awareness that intends to describe and explain the intertwining nature of the complex process underlying their EFL writing.
5. Numerical simulation of the through-thickness cracking of concrete cover due to steel reinforcing bars corrosion

Author:Mirzaee, MJ;Alaee, FJ;Hajsadeghi, M;Chin, CS


Abstract:Concrete cover cracking due to the corrosion of steel reinforcing bars is one of the main causes of deterioration in Reinforced Concrete (RC) structures. The oxidation level of the bars causes varying levels of expansion. The rebar expansions could lead to through-thickness cracking of the concrete cover, where depending on the cracking characteristics, the service life of the structures would be affected. In this paper, the parameters which influence the required pressure for concrete cover cracking induced by the rebar expansion due to corrosion have been investigated through detailed numerical simulations. ABAQUS finite element software is employed as a modelling platform where the concrete cracking is simulated by means of eXtended Finite Element Method (XFEM). The accuracy of the numerical simulations is achieved by comparison of the numerical results with experimental data obtained from the literature. The results reveal that the most effective parameter in the cracking process is the ratio of concrete cover depth to the rebar diameter. Using a previously proposed empirical equation and the numerical model, the time from corrosion initiation to the cover cracking is calculated and then compared to the respective experimental data.
6. Geometrical and material optimisation of deformed steel fibres: Spirally deformed fibres

Author:Hajsadeghi, M;Chin, CS


Abstract:This paper presents an optimisation procedure of geometrical and material properties of steel fibres using the validated three-dimensional nonlinear Finite Element (FE) pullout model previously proposed by the authors. The FE model is employed as a virtual laboratory unit to investigate the pullout performance of steel fibres with various shapes such as hooked-end and spirally deformed steel fibres. The preliminary FE pullout analyses imply that the optimisation of the fibre with spiral configuration (adjustment of geometrical and material properties of the fibre) could result in an efficient high-performing steel fibre; hence such a fibre is selected for the optimisation procedure. In order to re-validate the numerical pullout model and further adjust its nonlinear parameters for enhancing the simulations prediction, a set of experimental pullout tests are conducted on four spirally deformed steel fibres with different geometrical properties. Extensive parametric studies are performed on the material and geometrical properties of the fibre to examine their effects on the fibre pullout performance. Moreover, an empirical equation is proposed for the estimation of fibre efficiency and optimum design of spirally deformed steel fibres in which geometrical and material properties are taken into account.
7. Improving the properties of recycled aggregate pervious pavement blocks through bio-mineralization

Author:Liu, MD;Xia, J;Chin, CS;Liu, ZW


Abstract:Pervious concrete (PC) comprised of cement, water, coarse aggregates are widely used nowadays for sustainable and low impact pavement. The primary purpose of this study is to investigate the performance enhancement of pervious concrete blocks (PCB) containing recycled coarse aggregates (RCA) through microbially induced calcium carbonate precipitation (MICP). Two types of bacterial enhancement methods were adopted, which are PCB with pre-soaked RCA using bacteria solution and PCB with bacteria added mixing water. The properties of RCA, cement paste, and PCB were measured. The water absorption of RCA soaked in the bacteria and culture medium for 21 days was reduced by 10.41%%. Meanwhile, the porosity of PCB decreased by 15.70%%, and compressive strength increased up to 28.48%% when incorporating pre-soaked RCA. There was an increase of 57.23%% in compressive strength for hardened cement paste when bacteria were added in the mixing water. The compressive strength of PCB increased by 35.48%% when compared with PCB with normal mixing water. Both enhancement methods show promising results and realize the purpose of enhancing the properties of PCB containing RCA. (C) 2020 Elsevier Ltd. All rights reserved.
8. Development of a generic three-dimensional finite element fibre pullout model

Author:Hajsadeghi, M;Chin, CS;Jones, SW


9. A model for assessing the economic performance of construction waste reduction

Author:Hao, JL;Yuan, H;Liu, J;Chin, CS;Lu, WS


Abstract:Although a plethora of research has been conducted to investigate the economic performance of construction waste (CW) management, the vast majority of studies have concentrated on the economic feasibility of CW recycling, while ignoring the economic performance of CW reduction strategies and measures. Moreover, previous studies mostly focused on one specific waste stage for waste reduction, failing to envisage dynamic interactions among various factors inherent in different waste management stages including waste generation, on-site reduction, and waste disposal, which inevitably affects the effectiveness of implementing those management strategies. To address these research gaps, this study developed a system dynamics model to investigate the economic performance of CW reduction. The model is constructed based on the interrelationships of major factors affecting the economic performance of CW reduction and comprises three subsystems covering waste generation and disposal, waste reduction, and economic performance assessment. Data from a residential building project were used for model validation and simulation. The findings reveal four strategies to effectively promote the economic performance of CW reduction, including: enhancing waste sorting, reducing illegal dumping behaviors, promoting government's financial subsidy on waste recycling, and raising waste landfilling charge. Furthermore, model simulations inform that combining different waste reduction strategies could result in better outcomes than a single measure regarding CW reduction. This study is significant in revealing the interrelationships of factors affecting the economic performance of CW reduction. Meanwhile, the results are helpful for designing policies to improve CW reduction practice. (C) 2019 Elsevier Ltd. All rights reserved.
10. 我国大学本科生英语作文中元话语使用:基于语料库的纵向对比研究(英文)


Source:Chinese Journal of Applied Linguistics,2019,Vol.42

11. Changes in beliefs about language learning among Chinese EAP learners in an EMI context in Mainland China: A socio-cultural perspective

Author:Li, CL;Ruan, ZL


Abstract:This paper reports on a longitudinal study of changes in beliefs among Chinese EAP learners during a transitional period at an EMI university in Mainland China. Data were collected through questionnaires and semi-structured interviews, which were administered at two phases over one academic year. The study revealed significant changes in the learner beliefs after they studied EAP for an academic year at the EMI University. The changes were found to arise from the mediation of an array of socio-cultural factors in the EMI setting, which include content subjects taught in English, extracurricular activities, formative assessments, and important others such as teachers. The study illuminates the nature of learner beliefs as a socially situated construct, and has pedagogical implications for English language teaching in EMI contexts. (C) 2015 Elsevier Ltd. All rights reserved.
12. 再生骨料性质检测与再生透水砖配合比设计

Author:王欣弋;CS Chin;陆沈磊;夏骏;

Source:Jiangsu Building Materials,2018,Vol.

Abstract:通过测试四个月份的再生混凝土粗骨料的级配曲线、表观密度和水吸收率、压碎指标以及再生骨料成分分析,达到对连续生产的再生粗骨料性质的监测,通过监测结果选出最合适月份的骨料用作再生透水混凝土配合比设计的实验骨料。根据不同的骨灰比与水灰比,四组配合比实验设计并实施,检测了试块7 d、28 d的抗压强度以及透水率。实验结果表明,最佳配合比为单位体积混凝土中骨料含量1 258.00 kg/m~3、水泥含量340.00 kg/m~3、水含量为91.80 kg/m~3。
13. Partitioned Methods in Computational Modelling on Fluid-Structure Interactions of Concrete Gravity-Dam

Author:W. Z. Lim;R. Y. Xiao;T. Hong;C. S. Chin

Source:Computer and information science,2013,Vol.

Abstract:Fluid-structure interaction (FSI) has resulted in both complex applications and computing algorithmic improvements. The aim of this paper is to develop a better understanding of the fluid-structure interaction behaviour and the numerical coupling methods which can be used in analysing the FSI problem of a multi-physics nature computationally. There are two different systems in partitioned methods for coupling the fluid and structural domains which use strong and weak couple algorithms. Numerical results have been obtained on the hypothetical models for the close and open-spillways concrete gravity-dam. The two-way coupling partition method has been applied to the dynamic velocity flow and pressure using the ANSYS FEA software. A close comparison between the weak and strong coupled systems of two-way partitioned method has been made for the consideration of both close and open-spillways concrete gravity-dam.
14. 超高性能纤维混凝土空心配筋板抗弯承载力研究

Author:夏骏;Chee Chin;徐晓明;刘建忠;

Source:China Concrete and Cement Products,2017,Vol.

15. Life-cycle assessment of economic and environmental benefits of green residential buildings

Author:Zhikang Bao, Yuzhe Li, Jianli Hao, Weisheng Lu, Chee Seong Chin


Abstract:This paper aims to build up a framework to evaluate the economic and environmental benefits of GB by adopting life-cycle assessment. It starts with the extensive review of some key areas related to the study. Then, the components of economic and environmental benefits required being evaluated, and the methods to evaluate are introduced. Afterwards, based on the evaluation methods, two case studies in China with different certification level are adopted. From these two case studies, it is found green building will cause extra cost in the construction phase meanwhile economic and environmental benefits are generated in the operation phase. Green building is worth of being implemented because the payback period of the green building is much shorter compared with the service time. Additionally, the current green technologies are not mature enough to support the highest certification level of GB.
16. An Approach to Investigate the Fiber-Cementitious Composites Bond-Slip Mechanisms

Author:Chin, CS


Abstract:The composite behavior of fiber-reinforced cementitious composites is generally governed by the total contribution of individual fiber interacting with the cementitious matrix for which fiber-matrix bridging phenomenon is the main mechanism that would influence the energy absorption capacity of the material. This would mean that the overall characteristics of fiber-reinforced cementitious composites can be predicted if the fiber pullout behavior could be better understood. Fiber pullout tests are commonly proposed in the study of fiber-matrix bonding behavior, but such a test is always difficult to perform because it is highly reliant on the configuration design and there is no valid and standard testing technique to date. The specially designed fiber pullout testing fixture presented herein was shown to be able to evaluate the fiber-matrix bond-slip characteristics. The testing results clearly demonstrated that fiber with less deformity was shown to give higher dissipated pullout energy but lower maximum pullout load, whereas more heavily deformed fiber would result in a higher maximum pullout load but with less dissipated pullout energy that is due to fiber fracture during the pullout process. This article has provided an important insight on how fiber shape could influence the ductility of fiber-reinforced cementitious composites.

Author:Wang, X;Tate, D;Clin, C


Abstract:Papercrete, which uses waste paper as an alternative ingredient in concrete, is regarded as one type of mix design for green concrete that provide a new opportunity for waste paper disposal. However, the specific environmental influence of introducing waste paper has not been not clarified. Therefore, to evaluate the environmental contribution and feasibility of papercrete, based on the papercrete unit, the comparison of concrete production coupled with waste paper disposal is conducted according to a Life Cycle Assessment (LCA) analysis. The system of papercrete production discussed here covers raw material extraction to finished product. Three different treatments for waste paper combined with concrete production are considered in this study. With respect to most environmental indicators, the results indicate that papercrete by introducing waste paper achieves some environmental benefits. The major reasons that environmental indicators of papercrete improve are due to the reduction of natural resource utilization and emissions to air. In detail the environmental impacts of papercrete production acquire a remarkable improvement compared with impact of normal concrete production and the adoption of incineration disposal of waste paper. Nevertheless, the environmental benefits of papercrete production are not significant increased compared with the associated system when waste paper is collected for the manufacture of recycled paper, where most environmental indicators of papercrete production are only slightly increased.
18. Flexural Toughness of Concrete with High Performance Polymers

Author:Chin, CS;Xiao, RY


Abstract:Flexural toughness is a measure of energy absorption capacity and characterization of material's ability to resist fracture under flexure loads. Concrete, when unreinforced, behaves generally well in compression but its flexural behaviour particularly the post-peak performance is rather weak and brittle. Conventional method has been to include steel fibres to enhance the flexural capacity but was discouraged by their impractically heavy cost and weight constraints. This paper presents the use of high performance polymeric fibres as a cost-effective and lightweight potential alternative which also fits well into the modern era of sustainable construction seeing that they leaves substantially lower carbon footprint compared to steel. Mechanically deformed high performance polymer (HPP) made of 100 percent virgin polypropylene was adopted and incorporated into concrete mixes and its composite performance was experimentally investigated and compared to plain concrete and those reinforced by steel fibres. An analytical method to predict the overall flexural toughness response has also been proposed and verified.
19. Structural performance of optimised spirally deformed steel fibre

Author:Hajsadeghi, M;Chin, CS;Jones, SW


Abstract:The capability of steel fibres in stress transferring across the cracked sections (bridging effect) could be employed to enhance the concrete role (especially in tension zones) in the overall load bearing capacity of Reinforced Concrete (RC) members. However, the structural applications of Fibre Reinforced Concrete (FRC) is limited mainly due to the poor performance of existing fibres on the market (softening response). The continuous pullout load decay, i.e. softening response, cannot result in a major contribution of fibres to the ultimate load bearing capacity of RC members. In this paper, the structural contribution of an optimised spirally deformed steel fibre engineered by the authors possessing hardening response in normal concrete is examined experimentally. To this end, a structural testing programme consists of two sets of RC beams, i.e. shear -critical and flexure -critical, is designed such that the shear and flexural contribution of the spiral fibre can be assessed individually. Various experiment parameters are considered in the testing programme. The test results reveal that such a fibre could be employed as partial/full replacement for conventional reinforcement in RC beams. A shear design equation for RC beams incorporating the new fibre is also proposed.
20. A review on Agricultural Fibre Reinforced Concrete

Author:Nepal, B;Chin, CS;Jones, S


Abstract:The construction industry has undergone rapid development during the last few decades. This significant construction growth has substantially increased the demand for construction materials. Among all materials used in the construction industry, concrete is the most significant. Billions of tonnes of naturally occurring minerals are mined for the production of concrete which has left a big gap in terms of sustainability of the construction industry. To overcome this drawback, the search for durable and sustainable construction materials is currently needed. The world of concrete with fibres has been in continuous research and also in use. However, manmade fibres though enhanced the properties of traditional concrete, are not sustainable and economical. This paper presents a brief review of fibres from agriculture wastes that have been in research and application as potential next generation construction materials. The micro-structure and properties of Agriculture Fibre Reinforced Concrete (AFRC) are described and some current possible applications are mentioned. Various methodology, emerging trends as well as variations in modification techniques for agricultural fibre modified concrete are observed. Several recently published articles and technical papers dealing with such fibre modified concrete are critically reviewed.
Total 29 results found
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