• Management of construction waste in nuclear and thermal power plant projects in India

      Seethapathy, Sathiyamurthy; Henderson, Jane Helena (2017-11)
      Waste in construction is important both from the perspective of productivity and from environmental considerations. Mostly actual quantum of waste generation exceeds the percentage envisaged initially, causing needless utilization of both natural and human resources. It is understood from project and construction managers during site survey that there is plenty of scope for enhancing project productivity simply by minimizing waste out of construction and also saving the cost as well as extraction of natural resources. This paper attempts to identify the causes towards generation of waste of different types of building materials during various stages of construction in different power plant projects in India. Subsequent to identification, methods are proposed to mitigate the generation of construction wastes by adopting appropriate construction and management checks and methods, which allow waste reduction. The use of various building materials in different types of projects has different impact on the amount of waste generation, environment, and cost. Research data were gathered from the analysis of five power plant projects under construction or already completed in different states in India. The causes of such occurrences of each item and details have been analysed from the questionnaire survey and the same was processed for normalizing, data cleaning, and reliability analysis done through SPSS. The result of the first questionnaire was used along with site inputs/factual data to project the tabulation of perception versus reality. Furthermore, a second questionnaire was initiated for the validation of the above using non parametric statistic test and suitable recommendations were given to reduce wastage. The research paper reveals the major root causes for material wastage in construction of power plant projects and proper awareness to be created to the relevant project team by training. The findings of this paper would help in enhancing project productivity during construction, cost savings to the extent of 1.667% to 1.941% of total project cost and minimizing the extraction of natural resources.
    • A critical review of factors affecting manpower and equipment productivity in tall building construction projects

      Parthasarathy, Mudumbai Krishnaswamy; Murugasan, Rajiah; Murugesan, Kavitha (2017-12-05)
      Developing countries have seen an increase in construction of tall buildings in metropolitan cities due to space constraint. The construction of tall buildings in developing countries is undertaken as a combination of manpower and equipment to economize costs. This combination or interface of manpower and equipment, particularly in the basic activities such as concreting, reinforcement, formwork, blockwork, and plastering affects productivity of both the resources. This research aims at studying the factors affecting productivity of manpower and equipment at the micro level for the basic activities of construction for tall building projects. The factors have been further grouped and combined as sections. Responses collected through questionnaire survey from 109 personnel associated with the construction of 72 tall buildings in different geographies of India have been analysed using theoretical tools like frequency index, Spearman's rank correlation coefficient, and factor analysis. The factors have been prioritized in descending order of frequency indices. Based on analysis, it is found that factors in human and planning groups are more influential and affect manpower and equipment productivity significantly. Contract managers and cost engineers can use this study to make allowance while analysing productivity and estimating costs for tall buildings having combined usage of manpower and equipment.
    • Investigating the knowledge about health

      Narinder Menghre and Subashini Suresh; School of Technology, University of Wolverhampton (COBRA, 2013-10-10)
    • An Electron Microscope Study of Biomineralisation for Geotechnical Engineering Purposes

      Wilkinson, Stephen; Rajasekar, Adharsh (Springer, 2018-09-21)
    • New offsite production and business models in construction: priorities for the future research agenda

      Goulding, J.S.; Pour Rahimian, F.; Arif, M.; Sharp, M.D. (Taylor and Francis, 2014-03-11)
    • Assessing sustainability of employee suggestion schemes: a framework

      Lasrado, Flevy; Arif, Mohammed; Rizvi, A. (Emerald, 2015-11-16)
    • Creating a better healing environment in Qatari healthcare sector: Exploring the research agenda for the future

      Alhorr, Yousef; Arif, Mohammed; Bano, Tabassum; Egbu, Charles; Mazroei, Ahmed; Elsarrag, Esam (Elsevier, 2015-06)
    • Knowledge sharing maturity model for Jordanian construction sector

      Arif, Mohammed; Al Zubi, Mohammed; Gupta, Aman Deep; Egbu, Charles; Walton, Robert O.; Islam, Rubina (Emerald, 2017-01-16)
    • Developments in the United Kingdom Dispute Resolution Process

      Akintoye, Akintola; Renukappa, Suresh; Lal, Hamish (ASCE, 2015-02)
      It is generally recognized that the U.K. construction industry is associated with low profit, delay in payments, cash flow concerns, short-term relationships compared with other industries, and high levels of business failure. In particular, claims and disputes have proliferated in the industry largely due to unfair payment practices. Therefore, to encourage a swifter and more economic method of resolving construction disputes by way of adjudication, the U.K. Housing Grants, Construction and Regeneration Act 1996 (HGCRA) came into force on October 1st, 2011in England andWales, and November 1st, 2011 in Scotland. This study presents the HGCRA 1996 Act—highlighting its strengths and weaknesses—along with the new 2009 Construction Act. The study additionally presents awareness of the new Act, key reasons for amending the HGCRA 1996 Act, and the impact of key changes in the Act on the dispute resolution process. The paper concludes that the new Act is perceived as being more effective at improving cash flow in the construction supply chain and is expected to encourage parties to resolve disputes by adjudication—but it will have to overcome the historical fact that integration of such proposed changes in construction may be a complex issue.
    • Effect of wind characteristics on gas dispersion in porous media

      Wilkinson, Stephen (International Society for Porous Media, 2017-05)
      Greenhouse gases have the key role in global warming. Soil is a source of greenhouse gases such as methane (CH4). Radon (Rn) which is a radioactive gas can emit form soil into the buildings and causes health concerns. Different soil properties can affect gas emissions inside/from soil including temperature, humidity, air pressure and vegetation (Oertel et al., 2016). It’s shown in many cases that pressure fluctuations caused by wind play an important role in transport of gas in soil and other porous media. An example is: landfill gas emissions (Poulsen et al., 2001). We applied a novel experimental equipment for measuring controlled wind turbulence on gas transport in porous media. This set-up was utilized to evaluate the effect of wind turbulence on gas transport in relation to the depth of porous medium. Experiments were carried out with binary diffusion of CO2 and air as tracer gases with average vertical wind speeds of 0.02 to 1.06 m s-1. 13 different wind conditions with different speed and fluctuations were applied. Five oxygen sensors were places inside sample at different depths to measure air transportation within porous media and total of 39 experiments were carried out. Gas transport in porous media is described by advection-dispersion equation. Gas transport is quantified as a dispersion coefficient. Oxygen breakthrough curves as a function of distance to the surface of the porous medium exposed to wind were derived numerically with an explicit forward time, central space finite-difference based model to assess gas transport. We showed that wind turbulence-induced dispersion of gas is an important transport mechanism that can increase gas transport with average of 45 times more than molecular diffusion under no-wind condition. Power spectrum density is calculated for all the 12 wind conditions to determine strength vibration of all the wind speeds.
    • Construction industry legal risk identification for SMEs

      Charlson, Jennifer; Oduoza, Chike (Sweet and Maxwell, 2016)
    • An analysis of passive earth pressure modification due to seepage flow effects

      Hu, Zheng; Yang, Zhongxuan; Wilkinson, Stephen Philip; Wilkinson, Stephen; Zhejiang University, 12377, Department of Civil Engineering, Zhejiang University, B700, Anzhong Building, 866 Yuhangtang Road, Hangzhou, Zhejiang, China, 310058, ;; Zhejiang University, Department of Civil Engineering, B712 Anzhong Building, Zijingang Campus, Zhejiang University, 866 Yuhangtang, Hangzhou, China, 310058, ;; University of Wolverhampton, 8695, Department of Civil Engineering, Wolverhampton, West Midlands, United Kingdom of Great Britain and Northern Ireland; (NRC Research Press, 2017-09-13)
      Using an assumed vertical retaining wall with a drainage system along the soil-structure interface, this paper analyses the effect of anisotropic seepage flow on the development of passive earth pressure. Extremely unfavourable seepage flow inside the backfill, perhaps due to heavy rainfall, will dramatically increase the active earth pressure while reducing the passive earth pressure; thus increasing the probability of instability of the retaining structure. In this paper, a trial and error analysis based on limit equilibrium is applied to identify the optimum failure surface. The flow field is computed using Fourier series expansion, and the effective reaction force along the curved failure surface is obtained by solving a modified Kötter equation considering the effect of seepage flow. This approach correlates well with other existing results. For small values of both the internal friction angle and the interface friction angle, the failure surface can be appropriately simplified with a planar approximation. A parametric study indicates that the degree of anisotropic seepage flow affects the resulting passive earth pressure. In addition, incremental increases in the effective friction angle and interface friction both lead to an increase in the passive earth pressure.
    • MICP and Advances towards Eco-Friendly and Economical Applications

      Rajasekar, Adharsh; Moy, Charles K.S.; Wilkinson, Stephen (IOP Publishing Ltd, 2017-07)
      Biomineralization is a natural process aided by living organisms. Due to its applicability in ground improvement and bioremediation, Microbially Induced Calcite Precipitation (MICP) is an interdisciplinary field of study combining engineering, chemistry and microbiology. Bioremediation has been applied widely for contamination containment or removal, in this case it will be containment. MICP can also be applied to improve the efficiency of insitu bioremediation. Urease is an enzyme which can facilitate increased calcite precipitation. However the production of urease by bacteria and thus the resulting carbonate precipitation are inhibited by environmental factors including calcium concentration, bacterial concentration, pH and temperature. Under good conditions MICP can be used for heavy metal and radionuclide immobilization. However technologies such as bioconsolidation and biocementation require improvement such as time and cost. This paper highlights the application of MICP in addition to suggested improvements to make it more eco-friendly and sustainable.
    • Stimulation of Indigenous Carbonate Precipitating Bacteria for Ground Improvement

      Rajasekar, Adharsh; Moy, Charles K S; Wilkinson, Stephen (IOP Publishing, 2017-05)
      Calcite minerals are precipitated in soil through biomineralisation which can be either organic or inorganic in nature. Biomineralisation can be employed to improve ground conditions in its natural state. Usually, studies of applied biomineralisation are highly interdisciplinary involving expertise from engineers, chemists and microbiologists. In this paper, we study the potential of biomineralisation from indigenous bacteria present in soil. The soil samples were collected from a high permeable zone and the bacteria that inhabit the soil were stimulated at a temperature of 15°C. A cementation solution consisting of 500mM calcium chloride, urea and nutrient broth at a pH of 7.5 was added to the soil samples. Inorganic precipitation was found to be dominant and was more efficient when compared to organic precipitation. Carbonate precipitation data indicated that inorganic precipitation were 1.37 times better at carbonate formation in comparison to organic precipitation. Scanning Electron Microscopy analysis identified cementation bonds formed between soil particles. It was deducted that organic precipitation is dependent on temperature, and may take an extended time at such low temperature. The preliminary data presented in this paper suggests that the implementation of biomineralisation with in-situ microbes is promising but requires further laboratory and field investigation before being considered for engineering application.
    • Effect of air turbulence on gas transport in soil; comparison of approaches

      Pourbakhtiar, Alireza; Papadikis, K; Poulsen, T G; Bridge, J W; Wilkinson, Stephen (Geophysical Research Abstracts, 2017-05)
      Geophysical Research Abstracts (GRA) is the conference series publishing the abstracts accepted for the General Assemblies of the European Geosciences Union (EGU). It links the annual conference programmes listing programme groups, included sessions, and their contributions. The abstracts underwent an access review by the session conveners.
    • Effect of partial replacement of cement with slag on the early-age strength of concrete

      Tang, Kangkang; Khatib, Jamal; Beattie, Greg (Institution of Civil Engineers, 2017-02-17)
      Concrete structures are popularly used to provide open space areas that are often incorporated into the design of sports, social and industrial structures. One of the concerns with concrete structures, especially long-span concrete structures, is early-age thermal expansion and subsequent contraction as a result of the exothermic cement hydration reaction. Thermal contraction, externally restrained by vertical structural elements such as columns and shear walls, may cause thermal cracking if it exceeds the tensile strength of the concrete. The early-age thermal loading of cast-in-place concrete can be estimated through isothermal calorimetry, semi-adiabatic calorimetry and finite-element modelling (FEM). This paper discusses the efficiency of using FEM, based on the isothermal calorimetry results, for predicting early-age temperature development of in situ concrete. In addition, this work quantifies the beneficial effect of using ground granulated blast-furnace slag as a partial replacement of cement in structural concrete. The simulation results, validated via semi-adiabatic calorimetry, indicate reduced thermal loading due to the presence of slag. This can be taken as an advantage of using such slag in structural concrete.
    • Effect of wind turbulence on gas transport in porous media: experimental method and preliminary results

      Wilkinson, Stephen; Pourbakhtiar, Alireza; Poulsen, Tjalfe; Bridge, Jonathan (Wiley, 2017-01)
      Summary We demonstrate a novel experimental arrangement for measuring wind turbulence-induced gas transport in dry porous media under controlled conditions. This equipment was applied to assess the effect of wind turbulence on gas transport (quantified as a dispersion coefficient) as a function of distance to the surface of the porous medium exposed to wind. Two different strategies for the measurement of wind-induced gas transport were compared. Experiments were carried out with O2 and CO2 as tracer gases with average vertical wind speeds of 0.02–1.06ms−1. Oxygen breakthrough curves as a function of distance to the wind-exposed surface of the porous medium were analysed numerically with a finite-difference-based model to assess gas transport. We showed that wind turbulence-induced gas transport is an important transport mechanism that can be 20–70 times larger than molecular diffusion-induced transport. Wind conditions and properties of the porous medium had strong controlling effects on this relationship. Importantly, we show that even though wind-induced gas transport is greatest near to the wind-exposed surface, it can have marked effects on the variation in gas concentration at much greater depths.