A structural model for mitigation measures of critical cost overrun factors in highway projects in sindh province

Construction industry plays a major role in improving the socio-economic growth of any country. However, this industry is facing a serious problem of cost overrun globally and particular in Pakistan. Rapid growth in the construction sector in Pakistan has been observed along with many challenges, especially in highway projects. The most critical issues in highway projects are the cost overrun and lack of their mitigation measures. Hence, the objective of this research is to determine the critical factors of cost overrun, its significant mitigation measures and to develop a structural model of significant mitigation measures for critical cost overrun factors. The preliminary survey helped in identifying the critical factors of cost overrun in highway projects. In total, 64 common factors for cost overrun were identified from the literature review. Based on the common factors, a questionnaire was designed and distributed among the 30 selected experts to determine the critical factors of cost overrun. Out of 64 common factors, 24 were reported critical. The pilot study was carried out by developing a semi-structured questionnaire which was distributed among the same 30 construction experts for the purpose of determining the mitigation measures, which resulted in 113 measures. These mitigation measures along with the relevant 24 factors helped in the development of the final questionnaire to further narrow down the significant measures. This finalized questionnaire was distributed among 350 construction experts of highway projects to identify the significant mitigation measures for critical factors of cost overrun. The collected data was further used to develop a structural model for mitigation measures of critical factors of cost overrun by Smart PLS. Performance of the model has moderate explaining power as the predictive relevancy value is greater than 0.13. Significant mitigation measures of these critical factors were determined from the power loading of mitigations measures. This research would be helpful for construction managers in mitigating the relative risk to the project. Thus, it will directly benefit the construction community and contribute in raising the economy of the country

Factors of Delay in Highway Construction Projects In Pakistan

A project is called successful when that project is completed on approved time. However, due to so many reasons construction industry is failed to complete projects within approved time frame. Construction industry of Pakistan is facing a critical problem of delay in construction of highway projects which has adverse and negative impact to many stakeholders. The main objective of this research is to identify the most critical factors of delay in construction of highway projects and mitigation measures. A questionnaire was designed and distributed among 130 respondents of highway projects and they were asked to rank each factor according to experience. After analysis, mitigation measure of each factor was asked by same respondents. This research will help to stake holders to overcome identified factors of delay by using mitigation measures suggested by respondents.    Keywords: Construction of highway projects, Delay, Critical factors, Pakistan.

Mitigation measures for significant factors instigating cost overrun in highway projects

Construction industry has created numerous employment opportunities and playing a role model in economic growth of Pakistan. This industry is facing serious and critical problem of cost overrun especially in highway sector in country Pakistan particularly in Sindh Province. The purpose of this study is to identify mitigation measures for significant factors of cost overrun in highway projects of Sindh Province. In this study, mixed-mode research approach has been used. Quantitatively, a structured questionnaire based on 64 common factors of cost overrun from in-depth literature review was developed and distributed to30 selected respondents among the client, contractor and consultant having more than 15 years of experience in handling highway projects in Sindh Province. The collected data was statistically analyzed using SPSS where 8 most significant factors of cost overrun were identified. Qualitatively, the identified eight most significant factors were then incorporated in open ended questionnaire and distributed to 30 selected experts for them to write possible mitigation measures for each of the significant factors. The data was then analyzed through content analysis technique to rank the mitigation measures according to their substantiality. The results of this study would be helpful for construction practitioners to be used as reference in taking up appropriate measures in controlling cost overrun in highways projects in Pakista

Diagnostic accuracy of diffusion weighted MRI in differentiating benign and malignant meningiomas

Objective: To determine the diagnostic accuracy of DWI in differentiating benign and malignant meningiomas keeping histopathology as gold standard.Methods: This was a descriptive analytical study conducted at Radiology Department, DUHS/Dr. Ruth K. M. Pfau Civil Hospital Karachi, from August 2016 to March 2018.It included152 patients clinically suspected of meningioma on conventional neuroimaging. Imaging features of DWI were compared with histopathology findings. The diagnostic accuracy of DWI was calculated in terms of sensitivity, specificity, accuracy, PPV and NPV using histopathology as gold standard.Results: There were 59 male and 93 female patients with mean age of 55.38±9.8 years. Mean duration of sign and symptoms was 5.67±2.57 months. Out of 152 patients, 117(77%) and 35(23%) were differentiated into benign and malignant meningiomas respectively by DWI while 135(88.82%) and17(11.18%) patients were diagnosed respectively on histopathology. The sensitivity, specificity, PPV, NPV and accuracy of DWI of 84.4%, 82.3%, 97.4%, 40%, and 84.2% respectively keeping histopathology as gold standard.Conclusion: DWI features along with calculation of ADC values is a reliable non-invasive technique for differentiating benign and malignant meningiomas. However the low negative predictive value necessitates the use of histopathology

Triad of Supply Chain Orientation, Strategies and Competencies in Construction Industry

Construction sector is considered as the pillar of Pakistan's economic development. Numerous researchers have emphasized the role of supply chain orientation and supply chain strategies to uplift the sustainability within supply chains of construction industries. However, the lack of studies focused on the impact on supply chain orientation in Pakistan. Hence, this article examines the impact of supply chain orientation, supply chain competence and supply chain strategy of the Pakistani construction sector. The study adopted the non-probability sampling approach and 183 questionnaires survey data is collected from 75 construction firms in Sindh. The study is applied Partial Least Square-Structural Equation Modelling technique to analyze the collected data. The findings of the study revealed that all the relationships are positive and significant. The supply chain orientation (SCO) with supply chain strategy (SCS) with p<0.000, β=0.11, supply chain orientation (SCO) and supply chain competence (SCC) with p<0.000, β=0.34, SCO having a positive significant effect on SCC with p<0.000, β=0.22, SCS is playing a mediating role between SCO and SCC. It means that SCO improves SCS as a result p<0.000, β=0.15 and the relationship of SCS further improves SCC with p<0.000, β=0.11. The result shows that SCO is an important and significant tool in order to increase SCS and SCC. Hence, this study can help to device certain policies to cope up the issues that are the reasons for declining the construction performanc

Agronomic performance of Indian wheat varieties and genetic stocks known for outstanding chapati quality characteristics

The aim of the present study was to evaluate set of wheat genotypes in one location for their agronomic performance and chapati quality. The cultivars included the tall traditional wheat of the pre-dwarfing era, which were known to excel for chapati quality. This set also included varieties known to have good chapati quality, commercially grown wheats, advanced lines and genetic stocks excelling in one or other quality attribute. All these genotypes developed for different component traits were evaluated along with the recently released high yielding varieties to assess their quality. The mean chapati score of these genotypes revealed that the tall varieties had a distinct edge over others and are the best resource available for this trait. C306 had a high mean chapati score of 8.17 followed by C518, C591 and C273. The released varieties WG357, HD2733 and PBW343 were intermediate in chapati quality whereas the genetic stocks WH1103 and WH712 had lowest score in the group. Among other agronomic traits recorded the traditional varieties were tall and had lower yields than the recently released varieties. The tall varieties had a slightly higher test weight. The environmental conditions and the quantitative nature of the chapati quality did not auger well with the set of genotypes tested however, better and stable performance of the tall traditional varieties. C306 the wheat variety released in 1965 for cultivation has remained the best quality genotype over the years and was also established from this study

Most Common Factors Causing Cost Overrun with its Mitigation Measure for Pakistan Construction Industry

Cost overrun is known as the leading challenge for stakeholders of the construction sector. Like most countries, Pakistan also facing this challenge for the last few decades. Literature review was conducted and managed to identify 34 factors which contributed to cost overrun in the construction industry. These factors were used as the main content in designing the questionnaire. Respondents were required to rate these factors based on 4-ponits Likert scale on the degree of commonly occurred. Survey was carried out involved 130 stakeholders of the construction sector to determine main factors of the overrun. Data was collected, analysed statistically using the average index method and found 10 most commonly occurred of cost overrun factors for Pakistan construction industry are financial crisis faced by the client; mistakes in making proper estimation; faults in drawing; delay in getting approval from the client; poor planning by client; incompetency of contractor; poor supervision of the consultant; delay in payment to the contractor; communication gap between parties and natural disaster. These factors were further explained together with its mitigation measure. The findings of this study can help to Pakistani construction community in controlling the cost overrun for their construction projects

Comparative Study on Flexural Performance of Foamed Concrete Beam Containing Plastic Fibres

Foamed concrete is considered as light weight concrete which possesses lot of benefits in context of speedy construction, light weight and durability. In this study, foamed concrete beam, containing the plastic fibers were analyzed under flexural load by experimentally and also by finite element analysis in terms of load bearing capacity, load deflection profile and cracking pattern. The Finite element analysis (FEA) was conducted by utilizing ABAQUS software to simulate the foamed concrete beam under flexure load. The beam consist the dimension was 100mm thickness, 200mm breadth, 1000 mm length. The experimental and FEA outcomes were compared in context of the beam’s ultimate load, load deflection and cracking pattern. The outcomes demonstrate that the difference between ultimate loads was 5 to 8% between FEA and experimental results whereas the maximum deflection was 3 to 7 % decreased in FEA compare to the experimental analysis. The parametric was conducted by changing the reinforcement area the results demonstrates that by increasing the main reinforcement area the ultimate load was rises and deflection was decreases compare to the control sample. To approve a single suggestion, mouse over it and click "✔" Click the bubble to approve all of its suggestions. To approve a single suggestion, mouse over it and click "✔" Click the bubble to approve all of its suggestions. To approve a single suggestion, mouse over it and click "✔" Click the bubble to approve all of its suggestions. To approve a single suggestion, mouse over it and click "✔" Click the bubble to approve all of its suggestions. To approve a single suggestion, mouse over it and click "✔" Click the bubble to approve all of its suggestions. To approve a single suggestion, mouse over it and click "✔" Click the bubble to approve all of its suggestions

Thermo‑mechanical properties of various densities of foamed concrete incorporating polypropylene fibres

Concrete has been extensively used in the development of urban infrastructure works. However, it has the tendency to absorb solar radiations, and these radiations are released back into the air in the form of heat energy. Dense concentration of infrastructures releases more heat, causing urban heat island (UHI) effect in which the ambient temperature of the urban areas rises slightly than the surrounding areas. Tropical countries which have a hot climate throughout the year are more affected by the UHI effect. Therefore, thermal insulating materials need to be introduced in the field of concrete construction. Foamed concrete, which has air voids in its matrix, is a potential thermal insulating material. But due to reduced density, it, however, achieves lower strength. Polypropylene (PP) fibres are used to reinforce the foamed concrete and improve its compressive and tensile strengths. In this study, three different densities, 1400, 1600 and 1800 kg/m3, were cast, and 0.8% PP fibres were added. The thermo-mechanical properties were investigated in terms of thermal conductivity, surface temperature, compressive and tensile strengths with and without the addition of PP fibres. Based on the findings, the addition of PP fibres gained more strength and reduced thermal conductivity in the lower densities of foamed concrete. In contrast, it had an opposite impact on 1800 kg/m3 density. The addition of PP fibres also indicated that it could reduce the surface temperature of higher-density foamed concrete compared to lower densities