Demand For Construction Research Articles

Trenchless Goes Hybrid

The International Society for Trenchless Technology defines trenchless technology as “Underground construction methods of utility installation, rehabilitation, inspection, location and leak detection, with minimum excavation from the surface.” Today, trenchless contractor innovations and technology improvements are responding to the demand for cheaper and faster trenchless construction at a rapid pace. Innovation is expanding the range of subsurface conditions where existing equipment can achieve owner-prescribed design criteria. Business sectors with linear underground infrastructure are realizing benefits related to reduced cost, schedule, permitting conditions, and avoidance of right-of-way acquisition as a result of these technology advances and innovations in a maturing trenchless technology market. To understand the values of these advancements, some historical background on the technology offers perspective and context regarding their value.

A longitudinal analysis of collapsibility with predictions over the southeastern Loess Plateau in China

Loess presents very unique collapsible behaviour due to its special under-compactness, weak cementation and porousness. Many environmental issues and geological hazards including subgrade subsidences, slope collapses or failures, building cracking and so on are directly caused by the collapsible deformation of loess. Such collapsible behaviour may also severe accidents due to sinkholes, underground caves or loess gullies. Moreover, with the increasing demand of construction and development in the loess areas, an in-depth research towards effective evaluation of loess collapsibility is urged. Currently no studies have made attempts to explore a rather complete and representative area of Loess Plateau. This paper thus provides a novel approach on spatial modelling over Jin-Shan Loess Plateau as an extension to experimental studies. The in-lab experiment results have shown that shown that the porosity ratio and collapsibility follow a Gaussian distribution and a Gamma distribution respectively for both sampling areas: Yan’an and Lv Liang. This establishes the prior intuition towards spatial modelling which provides insights of potential influential factors on loess collapsibility and further sets a potential direction of the loess studies by considering an extra dimension of spatial correlation. Such modelling allows robust predictions taken into account of longitudinal information as well as structural parameters and basic physical properties. Water contents, dry densities, pressure levels and elevations of samples are determined to be statistically significant factors which affect the loess collapsibility. All regions in Lv Liang area are at risk of high collapsibility with average around 0.03, out of which roughly a third of them are predicted to be at high risk. Clear spatial patterns of higher expected collapsibility in the southwest comparing to the northeast are shown adjusting for influential covariates. On reference guidelines for potential policy makings, county-level regions with the highest expected loess collapsibility are also identified.

Modeling of cutting forces in 1-D and 2-D ultrasonic vibration-assisted milling of Ti-6Al-4V

To meet the modern demands for lightweight construction and energy efficiency, hard-to-machine materials such as ceramics, superalloys, and fiber-reinforced plastics are being used progressively. These materials can only be machined with great effort using conventional machining processes due to the high cutting forces, poor surface qualities, and the associated tool wear. Vibration-assisted machining has already proven to be an adequate solution in order to achieve extended tool lives, better surface qualities, and reduced cutting forces. This paper presents an analytical force model for longitudinal-torsional vibration-assisted milling (LT-VAM), which can predict cutting forces under intermittent and non-intermittent cutting conditions. Under intermittent cutting conditions, the relative contact ratio between the rake face and the sliding chip is utilized for modelling the shearing forces. Ploughing forces and shearing forces under non-intermittent cutting conditions are calculated by using an extended macroscopic friction reduction model, which can predict the reduced frictional forces under parallel and perpendicular vibration superimposition. The force model was implemented in MATLAB and can predict cutting forces without using any experimental vibration-assisted milling (VAM) data input.

Effect of Fine Glass and Quartzite Powder on Microstructure and Strength Properties of Concrete

Concrete is a vital construction material. It consumes a high number of natural resources like water, sand, and stones. Due to the increase in human population, the demand for new construction is at its peak and increasing day by day. Due to this, we utilize many natural resources. Researchers and scientists are searching for different ways in which they can reduce the amount or find alternates for use of other materials in the manufacture industry. The use of waste materials is one of them. In this, research has been done by using Waste glass powder and Quartzite powder in concrete to find alternates or partial replacements for natural resources in concrete. It was found that the joined effective use of glass powder and quartzite powder in concrete permitted the substitution of up to 15% glass powder and 30% quartzite powder. Various effects of these materials on concrete are discussed like effects on strength Characteristics, and microstructure studies like X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM). This study includes research and literature study from various journals paper and then the conclusion was made up.

A Study of Sandwich Reinforced Concrete – Foamed Concrete Floor Slabs

The development of housing construction demands an application of building materials which ensure necessary functional performance of structures, have high heat-insulating properties, are environmentally friendly and their use is economically appropriate. Simultaneous ensuring of mentioned indices is possible because of complex combined joining of building materials with different physical-mechanical properties. This article presents experimental determination of useful load for sandwich reinforced concrete – foamed concrete floor slabs. Sandwich reinforced concrete – foamed concrete floor slabs are the floor slabs which are composed of normal concrete, non-autoclaved foamed concrete and spatial reinforcement frame. Experimental determination of useful load was carried out on series that compose of four sandwich reinforced concrete – foamed concrete floor slabs. Experimental test of sandwich reinforced concrete – foamed concrete floor slabs was carried out under condition of pure bending that was achieved by applying to floor slab in one third of its span two concentrated forces equal in magnitude. Useful load for sandwich reinforced concrete – foamed concrete floor slabs was 33.23÷77.87 kN/m2. Sandwich reinforced concrete – foamed concrete floor slabs are proposed to be used in construction of housing and social structures.

A Systematic Literature Review on the Effect of Seawater as A Promising Material on the Physical and Mechanical Performance of Concrete

Concrete is made from freshwater, cement, and aggregate and the only material shared with mankind, flora, and fauna is freshwater. One of the most concerning problems the world has been facing over the last few decades is the rising demand for freshwater due to the increasing global population and depleting source of freshwater by 2050. In Malaysia, the population is expected to rise from 32 million people in 2020 to 40.50 million people in 2050, which would correspondingly increase the demand for domestic houses, industrial areas, and other building construction as well as increase the overall usage of freshwater. The utilisation of seawater has been applied in constructing buildings and infrastructures since the time of the Roman Empire and the structures still survive for more than 2000 years against chemical attacks and underwater wave force. Given that seawater is considered an alternative mixing agent in concrete production, research on seawater-based concrete has continued to gain interest from the scientific community and undergone swift development. Therefore, the aim of this study was to present a systematic literature review on the recent development of concrete with seawater as the mixing agent and its effect on the physical and mechanical performance of the concrete. A four-stage investigation criterion was conducted for the data collection from the Scopus database, which includes the search parameter, identification, screening, and writing. The screening of the literature retrieved 53 articles, which were then classified based on the physical and mechanical properties of the concrete. Based on the review, the use of seawater as a single mixing agent reduced the physical and mechanical performance of the concrete. However, the incorporation of seawater with special chemical admixture, mineral admixture, and reinforcement with certain treatment resulted in a higher performance of the concrete. Finally, the review highlighted the various potential studies that can be performed to investigate the utilisation of seawater in the construction industry while achieving a sustainable solution to preserve the environment.

Microbial Concrete-a Sustainable Solution for Concrete Construction.

In the ever-increasing demand of construction and construction materials worldwide, concrete is the most extensively used material for construction purposes almost next to the water. Therefore, there is a dire need of clean, green and durable concrete. Recently, an environmentally friendly strategy has been employed to manufacture bio-concrete by the usage of microorganisms in the traditional concrete to enhance its durability and compressive strength. In this review, we discuss the role of microbes in influencing the various properties of concrete such as compressive strength, flexural strength and tensile strength by reducing the concrete porosity and diminishing water absorption. The mechanism of microbial-induced calcium carbonate precipitation (MICP) in the traditional concrete by the action of microbes which resulted in the formation of bio-concrete as an improved building material has also been discussed. Additionally, an in-depth comparative analysis of the performance of bio-concrete with the traditional concrete synthesized from various industrial wastes such as silica fume, rice husk ash and metakaolin in terms of different properties such as compressive strength, flexural strength and percentage water absorption has been presented. This review highlights the impact of usage of microbes in the conventional concrete to produce novel and eco-friendly bio-concrete in construction technology.

Analysis of Labour Productivity and Determining the Parameters Which Affects it in Aluminium Formwork System

The construction industry is considered to be one of the rapidly growing industries of India. So, to fulfil such a vast and constantly increasing construction demand the labour productivity is the key factor to maintain client satisfaction, attract investment, and contribute by helping the nation with its economic growth. Aluminium system formwork is one economical and technical approach to effectively maintain productivity of labours on site. Various research studies have been conducted to compare different types of formwork system and the advantages and disadvantages of each type of formwork system are examined in terms of cost, duration, quality etc. There is no standard procedure to put a number on the efficiency of the site labour, using aluminium formwork system in the industry. So, the primary objective of this study is to find the practical labour productivity in aluminium formwork system and the factors affecting the labour productivity. For this, research is performed on Purva Silversands project, Pune, Maharashtra (Residential Project). Labour productivity and its variations could generate a greater impact on the project economy and project duration. Low productivity can decrease profitability and increases construction cost. This case study shows that the actual productivity observed is less than the target productivity in some of the months, the reasons for variation in target and actual productivity is examined and the factors that hamper the productivity mostly are natural (rain), improper management and any breakdown of machinery. Whereas, the maximum productivity achieved in a month is 10.36 sqm per man per day.

A multi-criterion decision analysis framework for sustainable energy retrofit in buildings

Old buildings are known to have poor energy performance and have limited improvement options as they approach their end-of-life. The demand for sustainable design and construction of new buildings and the desire to improve the performance of existing ones is rapidly increasing. Given numerous retrofit options available, it is imperative to determine which criteria should be used to arrive at a logical and impartial choice. Multifarious and conflicting factors such as environmental, economic, social, and technical performance further complicate the decision-making process. To address this, a systematic hybrid decision framework is developed to evaluate energy retrofit strategies and to identify a compromise retrofit scenario which considers all stakeholders involved. The Analytic Hierarchy Process (AHP) is used to determine the relative weight of each criterion based on stakeholders’ judgement while VIKOR is used to arrive at a compromise retrofit solution using relevant performance metrics. Although a Net-Zero Energy (NZE) scenario was proven technically feasible, this scenario was not identified as a compromise solution. Instead, three retrofit scenarios - on-site generation with high energy potential, mechanical/electrical with moderate energy potential, and building envelope with low energy potential showed good compromise for stakeholders. The proposed framework can be used as a tool by decision makers to arrive at compromise solutions that can benefit stakeholders.

INCORPORATION OF ADMIXTURES IN RECYCLED AGGREGATE CONCRETE: A REVIEW

The huge amount of annual concrete production poses significant harmful environmental impact. The demand for construction and concrete production consequently results in a huge demand for natural aggregate thereby causing great concerns for aggregate availability. Recycling waste concrete which often times end up in landfill is one of the major solutions to reduce its environmental effects. Waste concrete are crushed to desired sizes and used as replacement for natural aggregate to a certain degree in the production of new concrete. A reduction in strength has been reported after various researches with most recommending an optimum replacement percentage of 30% beyond which are decline in strength properties is evident. Thus, it becomes necessary to improve this performance and increase the amount of concrete waste reduction. To produce highperformance concrete, early researchers altered the watercement ration to achieve the desired results. Thereafter, they employed the use of chemical and mineral admixtures alongside specialised production process. In addition to performance improvement, Mineral admixture will function to substitute or reduce the consumption of Portland cement leading to a low impact, less energy consuming building material. This paper reviews the effect of admixtures on the mechanical properties of recycled aggregate concrete and possible areas for future research were identified and recommended.

Study on Engineering behavior of conventional cement concrete by partially replacing sea shell as Fine aggregate

In this study, it was investigate about the engineering behavior of conventional concrete of grade M25, by replacing the fine aggregate by partially with crushed sea shell. On because of progression in the field of infrastructure, the dearth of construction material becomes upsurge day by day. All the investigator was observe to find the substitute construction materials to meet the demand of construction in world wide. The reason behind is, while continuous utilizing of the natural raw material for construction decline the resource of those materials and further, it leads to affect the routine function of the earth and made drastic change in the life cycle of living beings. Therefore, it is obvious to find out the possible alternative material to suit for all type of construction. In this study, the sea shell was used as a fine aggregate in the method of crushed powder in an apparent proportion such as 10%, 20% and 30% replacing in the place of fine aggregate sand. The compression and split tensile behavior of sea shell aggregate mixed concrete comparatively with plain sand concrete was studied under different curing periods such as 7 days, 14 days and 28 days. It was shows that at 20% replacement of crushed sea shell aggregate provide the compressive strength of 35 N/mm2 at 28 days of curing nearly with the design strength of M25 grade conventional concrete. It was also noticed that, the percentage increase of crushed sea shell decline the strength of concrete as radically. Hence it was acclaimed that, the percentage of crushed sea shell as fixed equal or below 10 % to get a better strength of concrete.

Development of High-Performance Microfine Cementitious Grout with High Amount of Fly Ash, Silica Fume, and Slag

To develop high-performance microfine cementitious grout (HPMCG), the matrix [microfine Portland cement clinker (MPCC) + flue gas desulfurizing gypsum (MFGDG) + calcium carbonate (MCC)], microfine fly ash (MFA), silica fume (SF), and blast-furnace slag (MBFS) were selected. The viscoelasticity, fresh-state properties, mechanical performance, antipermeability, hydration mineral, and microstructure were investigated systematically. The 0%–3.0% naphthalene-based superplasticizer (N) and 1.0%–2.6% composite activator (CA) were applied, and the ratio of the water to binder (w/b) was selected as 0.8–3.0 by weight. The optimum component of HPMCG was acquired as the amount of MFA was 40% relative to that of the matrix, and the additional contents of SF and MBFS were 10% and 30%. The amounts of N and CA were suggested as 1.5%–2.0% and 2.4%, respectively. After optimization, the maximal flexural strength (FS) and unconfined compressive strength (UCS) of the HPMCG (91-day) can achieve 7.29 and 31.65 MPa; nearly all of the calcium hydroxide reacted, and more gels were generated. More generated gels interconnected with each other to form dense network structures, there were few microvoids and pores, and the entirety of the microstructure was enhanced obviously. The optimized HPMCG surpassed the expectation. The optimized HPMCG has superiorities, such as excellent viscoelasticity, good fluidity, high stability or stone rate, high mechanical strength, good antipermeability, an advantageous mineral component, and a microstructure. In civil engineering, they can satisfy high standard demands of construction and repair grouting practices.

κ-Carbide assisted nucleation of B2: A novel pathway to develop high specific strength steels

Controlling morphology of B2 phase as nano-sized particles that are homogenously distributed within austenite matrix has been remained as a challenging task particularly for hot rolled lightweight steels, where the nucleation sites for B2 precipitation are less abundant than in cold rolled ones. Utilizing the phenomena occurring in age-hardenable aluminum alloys, i.e., heterogeneous nucleation of precipitates from pre-existing GP zones, here we solved this challenge by using κ-carbide nanoparticles to promote the formation and to engineer the morphology of B2. This strategy has been applied to a hot rolled Fe-21Mn-10Al-1C-5Ni model steel resulting in the formation of a large fraction of B2 nanoparticles (sizes of 20-500 nm) uniformly distributed within austenite grains. Besides their contribution to precipitation strengthening, these B2 nanoparticles lead to a dramatic improvement of work hardening capability of the steel. As a result, novel precipitation hardened hot rolled lightweight steel with excellent combination of ultrahigh specific strength and ductility has been fabricated. Such properties of the present steel are not only better than those of other hot rolled lightweight steels strengthened by B2 and/or κ-carbide but also comparable to those of the steels subjected to additional cold rolling, and it is expected to expand the applications of B2-strengthened steels in response to an increasing demand for lightweight constructions.

Discuss the Application of Project Management in Construction Project Management

Along with the development of social economy in recent years, all walks of life in society have made obvious progress and development, such as the construction industry. At present, people’s demand for housing construction is getting higher and higher, and housing construction has gradually developed into a necessity of life from the former luxury goods. The increase in the demand for housing construction in the market has brought new life to the construction industry, and the number of similar construction enterprises in the construction industry is increasing. This also means that construction enterprises have to constantly control the quality of their projects and improve their competitiveness in order to survive in the fierce construction market.

Proposed Business Scheme for Small and Medium Architectural Consultant Using Blockchain Paradigm (Case Study: Studio Kano)

Developments in Indonesia are growing along with the increase in population. The high demand both in architecture and construction is an excellent opportunity for architectural business. Unfortunately, the development was not supported by proper preparation of financial allocations. As a result, many projects were delayed or even stalled. Moreover, this problem has negative impacts on various parties, such as architects and contractors.
 This paper formulates a new architectural business scheme for Studio Kano as a newcomer architectural consultant who often experiences problems during the process. The majority of this problem is due to the client's financial condition and causes a difference between the results and the initial design. At first, Studio Kano needs to increase the company's productivity and minimize disruption in project development, especially from the financial issues, by analyzing the company's current business situation using two analytical approaches; Business Process Analysis and Value Proposition.
 The finding from conducted analysis determines a new architectural business scheme for Studio Kano using the Blockchain paradigm. It will underpin to maintain its design characteristics, maximize productivity, and minimize project development disruption, especially in payment issues.

Building stock dynamics and the impact of construction bubble and bust on employment in China

AbstractThe rapid urbanization and building boom in China in the past decades provided not only massive residential and nonresidential floor space, but also millions of jobs especially for migrants from rural areas. However, such high‐speed growth of building stocks is not expected to continue forever and its dynamics, especially declining, may affect the job market of the construction sector and further China's social stability. Here, we extended a dynamic material flow analysis (dMFA) model that characterized the building stocks and flows to forecast the province‐level direct labor demand in construction, installation, and decoration in mainland China from 1950 to 2050. We show that as China's per capita building stocks start to saturate in the next decades, building inflow will decrease with a speed of 2.6–2.7 billion m2/year, corresponding to a decrease of direct construction employment by 2–3 million by 2050. The flow of migrant workers from Central South and Southwestern China to construction in the Southeastern coast of China will remain until 2050. Our results exemplify the usefulness of dMFA for labor demand forecasting and call for proper governmental plans and policies in advance to train migrant workers for new labor markets and potential re‐employment in face of the construction bubble and bust.

Methodology of Controlled Crack Introduction in Cementitious Materials

Crack formation is a common and generally inevitable phenomenon in the field of concrete structures. On the other hand, the ever-increasing demand for sustainable construction, thus the structures durability, has led researchers to propose and investigate various crack-sealing methods. This study deals with the key aspect of these investigations – the in-vitro creation of cracks. A large number of the conducted studies have been carried out on artificially cracked specimens, and various methodologies of the controlled crack introduction were presented; however, no specific method was clearly preferred. In this paper, several approaches to the crack introduction are applied: cracking through compressive loading, tensile loading, and 3-point bending. Further, different types of specimens are presented: plain concrete, reinforced with short and long steel fibers, and reinforced with steel rod. The achievable crack characteristics, such as widths or its stability over time, are evaluated and compared. This study thus provides valuable overlook of the possible approaches to the controlled crack creation and points out their potential and limitations. Based on the comparisons presented in this paper, the long steel fiber reinforced concrete specimens subjected to 3-point bending are identified as the most appropriate method of crack induction.

Research on Survey for Finding Effects of Covid-19 Pandemic on Construction Industry

This research paper is mainly carrying purpose of finding the effects of Covid-19 pandemic on construction industry. This is achieved through a methodology which involved online questionnaire survey based on the quantitative assessment of the impacts as well as review of the professionals who are the respondents. The respondents are directly related to construction activities and also possess good credibility for their work and academic qualification. The survey has been designed and hosted via google forms and shared with respondents mentioned earlier. The survey is designed so as the researcher gets insights related to even minute problems which were faced by the professionals during the hard times of pandemic. Survey is also taking care of gathering information related to probable losses caused to the respondents by asking an open-ended question related to work. Further the gathered data has been explained theoretically as well as represented visually by bar graphs and pie charts etc. From obtained results, a badly affected conditions pf construction industry come in light. Majority of respondents were forced to fully or partially stop their projects. Other issues which are highlighted by more than one third of the respondents are, higher operating cost at site, decreased demand of construction during Covid-19, supply chain provider’s problem, black marketing. Actual number of affected professionals is a dark side in such difficult time. Keywords: Professionals, business, experience, data, questionnaire survey, black

Micro-notches as a novel connection system for timber-concrete composite slabs

Timber-concrete composite slabs are more and more in use: the combination of timber and concrete combines the advantages of both materials and offer a valid solution for the increasing demand for sustainable construction. The connection between timber and concrete is the crucial element, yet its potential regarding material and time expenses is not exploited. This paper presents the novel connection system micro-notches, an interlocking concept between timber and concrete with indentations in the millimetre range. Micro-notches provide a continuous shear transfer without additional steel fasteners such as screws or dowels. The paper presents the development of the micro-notch concept in an extensive experimental program supplemented with analytical and numerical models, a calculation model, and practice-relevant guidelines. The results of the investigations show that micro-notches feature an approximately rigid composite action between timber and concrete and a sufficient shear strength for the use in office and residential buildings.

PEMETAAN PENURUNAN ELASTIS FONDASI TIANG BERDASARKAN DATA SONDIR KOTA PEKANBARU

<span class="fontstyle0">Pekanbaru City has developed quite rapidly. Therefore, local governments are aware of the<br />high demand for multi-story building construction, so that buildings built with more than two floors<br />are required to conduct a land subsidence test. The load of a structure will be transmitted by the<br />foundation to the ground, where the soil is expected to be able to support the load. The soil subsidence<br />test is obtained from the sondir test data or also called the Dutch Cone Penetration Test (DCPT)<br />which is used to determine the profile into the soil continuously with the value of cone tip resistance<br />and blanket resistance (Wafi et al., 2013).The purpose of this study is to analyze the calculation of<br />the settlement of a single pile foundation based on the foundation bearing capacity data from the<br />sondir data obtained from the Riau University Laboratory using the elastic settlement method. The<br />research stages carried out are reviewing theories related to piles, then collecting data including<br />data on the carrying capacity of the foundation and sondir data. The final stage is conducting<br />calculation analysis. The results of this study obtained a map of the elastic settlement of the pile<br />foundation at a depth of 6 meters, 12 meters and 18 meters</span>