Prof. D. A. R. Dolage (original) (raw)

Papers by Prof. D. A. R. Dolage

This study provides the results of a survey of major contractors engaged in the Sri Lankan constr... more This study provides the results of a survey of major contractors engaged in the Sri Lankan construction industry. It is aimed at identifying common risk elements affecting construction industry projects, determining how they are apportioned between the owner and the contractor, and quantifying and ranking their significance. The previous studies provided a list of 52 risk elements and with the help of a pilot study it was reduced to manageable 25 risk elements having a great relevance to the Sri Lankan construction industry. Altogether 72 respondents selected from among major contractors in Sri Lanka (C1 to C4) were involved in the questionnaire survey of the study. The analysis of the results show that only some risk elements are apportioned more to one party (apportionment of at least 65%) either contractor or owner. Shortage of labor, materials, tools and equipment (82%), Low productivity of labor and equipment due to complexity of work (78%), Labor disputes & trade union action ...

This paper summarises the research work on determining suitability of rice husk ash (RHA) to part... more This paper summarises the research work on determining suitability of rice husk ash (RHA) to partially replace cement in manufacturing cellular masonry blocks. The particle size distribution and chemical composition of RHA were measured for samples taken at different temperatures. In this research, mixtures have been prepared in combinations of four binder-sand ratios namely 1:3, 1:4, 1:5 and 1:6, three water-binder ratios namely 0.4, 0.5 and 0.6 and five levels of cement replacement with RHA namely percentages of 0, 5, 10, 15 and 20 by weight. One hundred and twenty cubes were cast (4x3x5x2=120) and tested for compressive strength at 7 and 28 days. Based on the compressive strength values, 1:5 binder-sand ratio was chosen as the appropriate mix proportion to cast cellular masonry blocks for different water-binder ratios namely 0.5 and 0.6 as per SLS 855Part 1:1989. RHA was blended with cement in percentages of 0, 5, 10, 15 and 20 by weight in producing cellular masonry blocks of size 390 x 190 x 200 mm. These were tested for water absorption in addition to compressive strength. The compressive strengths of cellular masonry blocks at 7, 14 and 28 days for 1:5 binder-sand ratio, water-binder ratio 0.5 and 5 per cent cement replaced with RHA were 2.05 N/mm2, 2.24 N/mm2 and 3.37 N/mm2 respectively. Likewise the values for 1:6 binder-sand ratio for water-binder ratio 0.5 and 5 per cent cement replaced with RHA were 1.6 N/mm2, 2.18 N/mm2 and 3.24 N/mm2 respectively. The minimum compressive strength as per SLS 855 Part I: 1989 is 1.2 N/mm2. The water absorption rates for water-binder ratios 0.5 and 0.6 are 9.8 and 10.5 respectively, which are within limits; the allowable limit is 10-15% as per BS EN 1996-1-1. The study concludes that 15 per cent cement replacement level is permissible

Engineer: Journal of the Institution of Engineers, Sri Lanka

River sand is the most widely used fine aggregate in civil engineering constructions in Sri Lanka... more River sand is the most widely used fine aggregate in civil engineering constructions in Sri Lanka. Traditionally river sand is extracted from rivers and streams. In the Jaffna peninsula there are no rivers or streams flowing through the area. Sand deposits in rivers are depleting in Sri Lanka, especially in the Southern region, as the annual demand for sand is very high due to rapid increases in civil constructions. The total demand of sand in Jaffna is met by the supplies of sand from the Southern region. This has led to large scale sand mining in the southern part of the country. As a result, most river banks have been eroded. Therefore, it is necessary to minimize sand mining, which is hazardous to environment.

Engineer: Journal of the Institution of Engineers, Sri Lanka, Dec 31, 2019

Engineer: Journal of the Institution of Engineers, Sri Lanka, 2015

The Social Safeguard Management Programme (SSMP) has become a key component of irrigation related... more The Social Safeguard Management Programme (SSMP) has become a key component of irrigation related rehabilitation projects. This paper reviews a renewed approach to developing SSMP that has been adopted in the rehabilitation of four reservoirs coming under the DSWRPP, where water releases had to be suspended temporarily to enable the rehabilitation. The SSMP has been designed in such a way that livelihood support assistance is provided to 8,344 affected families in the downstream communities. The conduct of Social Impact Assessment and the development of Livelihood Support Assistance (LSA) plans are illustrated. The LSA plan has four sub plans namely Wage Assistance Plan, Alternative Crops Plan, Domestic Water Use Plan and Gender Action Plan. The affected people have contributed to the economy by working in the rehabilitation work and saving foreign exchange by cultivating alternative crops. The paper presents ample evidence of the level of contentment and happiness of the farmers at the end of the programme, they being made responsible for the development and implementation of the LSA plans. The main argument offered in this article is that the programmes to assess and mitigate socioeconomic impacts should primarily take into account the perspectives of the people without exclusively relying on specialists or technocrats.

Engineer: Journal of the Institution of Engineers, Sri Lanka, 2016

This research paper explores the possibility of using indigenous woody plant materials as the rei... more This research paper explores the possibility of using indigenous woody plant materials as the reinforcement for composite members in cement mortar. The objectives of the study are to ascertain the stress-strain relationship and volumetric stability of indigenous woody plant materials with respect to locally adopted seasoning techniques. The survey identified six woody plant materials namely Veval, Una, Tharana, Eraminiya, Kooratiya and Dodanpana, which are worthy of being investigated based on past knowledge. The two locally adopted seasoning techniques investigated in this research are air drying and heat treatment. The specimens subjected to air drying for seasoning record higher tensile strengths than the heat treated, with respect to all six materials investigated. While Dodanpana records the lowest variation in cross sectional area, Tharana, Kooratiya and Una also show relatively high stability in relation to shrinkage. Three out of the six woody plant materials investigated, Kooratiya Tharana and Dodanpana can be recommended as suitable to be used as reinforcements, in terms of tensile strength, cross sectional area stability and length stability. These materials could be utilized for replacing mild steel reinforcements in Reinforced Cement Mortar (RCM) composite members. RCM could be effectively adopted for relatively low stress level applications in rural areas, where the villagers can easily obtain such woody plant materials and season the same using traditional methods.

Engineer: Journal of the Institution of Engineers, Sri Lanka, 2016

The purpose of this study is to select a more effective technique from 'upstream cutoff' and 'gro... more The purpose of this study is to select a more effective technique from 'upstream cutoff' and 'grouting treatment' for the control of seepage through the Vendarasankulum reservoir. Using engineering judgment, empirical and theoretical knowledge, trapezoidal cross sectional dimensions of layers of different soil materials were determined. For example, the cross section at 490m (from left); SC layer on the U/S side slope has widths, 3m and 12m at bund top and bottom respectively; clay layer in the core has widths 12 m and 3 m at the top and bottom respectively. The effective fetch (1.72 km) and thereby the maximum wave height (0.84m) were computed in order to extract values for thicknesses of riprap (0.45 m) and bedding layer (0.30m). Grouting treatment involves clay-cement grouting in the overburden and 6m deep cement grouting in the rock, requiring a total of 296 grout holes. While the estimated cost of construction of the upstream cutoff is SLR 30.3 million, the same for grouting treatment is SLR 11.3 million, indicating the former option would cost 168 percent more. Therefore, grouting treatment is more economical and sufficient, although upstream cutoff could offer better seepage control.

Engineer: Journal of the Institution of Engineers, Sri Lanka, 2006

There are 3 different versions of tile laying techniques adopted in the industry at present and n... more There are 3 different versions of tile laying techniques adopted in the industry at present and no attempt has been made so far to evaluate these techniques and thereby to promote the most desirable technique. Of the three techniques, in the first two, tiles are fixed on to the already hardened bed using cement slurry. These two techniques differ from one another because one uses a rectangular shaped toothed trowel while the other uses the standard mason's trowel to apply the cement slurry. In the case of the third technique, tiles are fixed on to fresh mortar bed after applying a coating of lean cement slurry. Data was collected from 15 sites; five for each technique to determine the cost effectiveness of each technique. Out of the above, 12 sites were considered to evaluate the performance of each technique with respect to quality. The results obtained after the analysis revealed that the third technique which involves fixing of tiles soon after the mortar bed is laid, is the most cost effective since it consumes less cement and sand. The quality of tile laying was assessed in terms of two parameters namely, bondage and level. The above technique is the best with respect to bondage of tiles with the substrate. However, this technique performs poorly when it comes to maintaining the uniformity of levels of individual tiles. This is due to the deformability of fresh mortar bed on which tiles are placed. The tilers who applied this new technique were not entirely conversant with it. Therefore, the results obtained could be further improved by engaging tilers skilled in this technique. If the public and private sector stakeholders' sponsorship is forthcoming this technique can be promoted and personnel to be engaged can be trained so that it can be applied on a mass scale.

Engineer: Journal of the Institution of Engineers, Sri Lanka, 2016

In an effort to ease off the financial burden on contractors, a government policy was enacted on ... more In an effort to ease off the financial burden on contractors, a government policy was enacted on first November 1997, to reduce the existing ten percent penal sum of the performance bond to five percent. There was no overall justification for this decision. The primary aim of this study is to explore the adequacy of indemnity afforded by the penal sum of five percent, for the performance bond used in construction contracts. The sample of the study has been confined to 25 state sector building projects. These projects were either completed with the same contractor with a time extension or with a new contractor after terminating the former. The main contribution of the study is the construction of several confidence intervals for the population mean of 'total loss to the client as a percentage of the contract sum'. The study reveals a more pragmatic and compromising penal sum of seven and half percent when a conducive environment prevails to procure performance bonds. Still contractors do not have cheaper and easier ways of obtaining performance bonds. Further, performance bonds are seldom called on. Hence, the study recommends that the prevailing five percent penal sum remain the same. The study also has highlighted the problems the contractors encounter in procuring performance bonds from bond providers (sureties) such as banks, insurance companies and the Construction Guarantee Fund.

Engineer: Journal of the Institution of Engineers, Sri Lanka, 2016

This paper investigates the many causes of delays in the pre-construction phase of State Sector B... more This paper investigates the many causes of delays in the pre-construction phase of State Sector Building Projects. The investigation was done through a questionnaire based survey that involved Clients, Consultants and Contractors to evaluate the causes of delays. The technique of Relative Importance Index was adopted to rank the causes of delays in a descending order. Based on this evaluation the causes of delays were identified and ranked, and two remedial measures were developed. Firstly, a process diagram for the pre-construction phase was designed in order to establish the systematic process and to represent useful inputs and outputs at various stages of the process. Secondly, a checklist was formulated in an effort to ensure that important actions are taken at the correct stages to minimise the opportunity for delays. Also, the study proposes suitable additions/ amendments to the 'Form of Agreement', an ICTAD publication, and recommends to make the use of these remedial measures mandatory.

Engineer: Journal of the Institution of Engineers, Sri Lanka, 2015

This study focuses on determining important causes of construction delays attributable to contrac... more This study focuses on determining important causes of construction delays attributable to contractors in large construction projects in Sri Lanka and the degree of severity of these causes. The causes of delay have been found based on the perceptions of the engineers working for three state affiliated establishments namely, Department of Buildings (BD), Road Development Authority (RDA) & National Water Supply and Drainage Board (NWSDB).The severity of each cause of delay is measured and represented through a severity index (SI). The causes of delay were determined and ranked in the descending order of severity. According to the findings, Poor project planning & scheduling (SI-82.54) is the most influencing factor causing delays in construction projects. In the descending order of severity, the other causes of delay are Low profit margin (SI-80.28), Inadequate cash flow management (SI-78.31), Handling of too many project sat a given time (SI-75.21), and Incompetence of the key staff (SI-74.93).Spearman rank correlation coefficient was used to determine the degree of agreement on the ranking of severity of causes of delay among the organisations. The highest degree of agreement is between BD &NWSDB (0.77). There exists an intermediate degree of agreement between RDA & NWSDB (0.73) and the lowest is between RDA & BD (0.70).The study finally makes 10 recommendations to mitigate construction delays.

Technology and Investment, 2012

This paper explores the impact of the adoption of Flexible Manufacturing Technology (FMT) on the ... more This paper explores the impact of the adoption of Flexible Manufacturing Technology (FMT) on the Malaysian Manufacturing Industry. The Principal Component Analysis has been adopted to extract the most appropriate underlying dimensions of FMT to use in place of the eight FMT variables owing to the potential multicollinearity. The study has been conducted within FMT intensively adopted 16 three-digit industries that encompass 50 five-digit industries covering the years 2000-2005. The results obtained from the two scenarios, one, including the industry fixed effects dummy variables and the other without these, are contrasted. It is established that the model that included the industry fixed effect dummy variables has a greater explanatory power. The two principal components that account for the greater variation in FMT show positive and moderately significant relationship with PCM. The study provides sufficient evidence to conclude that FMT has a direct and moderately significant relationship with PCM.

Technology and Investment, 2012

This paper examines the impact of the adoption of Flexible Manufacturing Technology (FMT) on the ... more This paper examines the impact of the adoption of Flexible Manufacturing Technology (FMT) on the Technical Efficiency of Malaysia Manufacturing Industry. Owing to the potential multicollinearity, the Principal Component Analysis has been adopted to extract the most appropriate underlying dimensions of FMT in an effort to substitute the eight FMT variables. The study has been conducted within FMT intensively adopted 16 three-digit industries that encompass 50 five-digit industries covering the years 2000-2005. The results obtained from the two situations, one, including the industry fixed effects dummy variables and the other without these, are contrasted. It is found that the model that included the industry fixed effect dummy variables possesses a greater explanatory power. The two principal components that account for the greater variation in FMT show positive and moderately significant relationship with TE. The study concludes with sufficient evidence that FMT has a direct and moderately significant relationship with TE.

Engineer: Journal of the Institution of Engineers, Sri Lanka, 2014

Engineer: Journal of the Institution of Engineers, Sri Lanka, 2014

The main purpose of this study is to identify the significant causes of time overrun in construct... more The main purpose of this study is to identify the significant causes of time overrun in construction phase of building projects handled by the Department of Engineering Services (DOES) of Sabaragamuwa Provincial Council (SPC) and to propose mitigative measures. The preliminary investigation of this research revealed that 80% of the building projects handled by the DOES are not completed within the agreed contract period. The study determines 51 factors causing time overrun in the context of the DOES, which is the basis of the study. The perceptions of clients, consultants and contractors regarding frequency of occurrence and severity of these factors were obtained using questionnaire. Using the indices of frequency, severity and thereby the indices of significance were computed for all the factors. 'Rainy weather', 'poor liquidity of the contractor' and 'inaccurate planning and scheduling of projects are identified by all parties as the most significant factors causing time overrun. According to the views of both clients and consultants, 'contractor related factors' are the most significant causes of time overrun. As for the degree of agreement of perceptions on delay causes. the highest is between clients and consultants (68%) and the lowest between the contractors and clients (50%). Finally, the research makes propositions separately for each party in the contract in order to mitigate the respective contribution towards time overrun

Economic Modelling, 2010

This paper investigates the influence of the adoption of Flexible Manufacturing Technology (FMT) ... more This paper investigates the influence of the adoption of Flexible Manufacturing Technology (FMT) on the Total factor Productivity Growth (TFPG) of Malaysia Manufacturing Industry. The Principal Component Analysis has been adopted to extract the most appropriate underlying dimensions of FMT to use in place of the eight FMT variables owing to the potential multicollinearity. The study has been conducted within FMT intensively adopted 16 three-digit industries that encompass 50 five-digit industries covering the years 2000-2005. The results obtained from the two situations, one, including the industry fixed effects dummy variables and the other without these, are contrasted. It is established that the model that included the industry fixed effect dummy variables has a greater explanatory power. The two principal components that account for the greater variation in FMT show positive and moderately significant relationship with TFPG. The study provides sufficient evidence to conclude that FMT has a direct and moderately significant relationship with TFPG.

British Journal of Applied Science & Technology, 2013

The aim of this study is to test the relevant properties of offshore sand obtained soon after dre... more The aim of this study is to test the relevant properties of offshore sand obtained soon after dredging and to examine the effects on chloride levels of offshore sand when fresh water is drained to simulate average monthly rainfalls. The findings are valid for offshore sand that does not require washing particularly to remove organic matter and other contaminants. As per the results of sieve analysis, grading of the offshore sand is within the limits specified in BS 882:1992. The compressive strength of grade 25 concrete which is the mostly used structural concrete is also within the acceptable limits. The shell content of offshore sand for shells finer than 10 mm and coarser than 5 mm is 6.5 per cent. This is far below the 20 per cent limit specified in BS 882:1992. For grade 25 concrete produced with OPC, an allowable limit of 0.101 per cent by weight of sand was computed for chloride content in offshore sand. The chloride content of offshore sand obtained soon after dredging was 0.04%. Even a rainfall as low as 9.9 mm can reduce the chloride content (range from 0.01 to 0.05) to levels far below the allowable limit (0.101). Rainfalls as high as 581 mm could wash away chlorides almost completely

This study provides the results of a survey of major contractors engaged in the Sri Lankan constr... more This study provides the results of a survey of major contractors engaged in the Sri Lankan construction industry. It is aimed at identifying common risk elements affecting construction industry projects, determining how they are apportioned between the owner and the contractor, and quantifying and ranking their significance. The previous studies provided a list of 52 risk elements and with the help of a pilot study it was reduced to manageable 25 risk elements having a great relevance to the Sri Lankan construction industry. Altogether 72 respondents selected from among major contractors in Sri Lanka (C1 to C4) were involved in the questionnaire survey of the study. The analysis of the results show that only some risk elements are apportioned more to one party (apportionment of at least 65%) either contractor or owner. Shortage of labor, materials, tools and equipment (82%), Low productivity of labor and equipment due to complexity of work (78%), Labor disputes & trade union action ...

This paper summarises the research work on determining suitability of rice husk ash (RHA) to part... more This paper summarises the research work on determining suitability of rice husk ash (RHA) to partially replace cement in manufacturing cellular masonry blocks. The particle size distribution and chemical composition of RHA were measured for samples taken at different temperatures. In this research, mixtures have been prepared in combinations of four binder-sand ratios namely 1:3, 1:4, 1:5 and 1:6, three water-binder ratios namely 0.4, 0.5 and 0.6 and five levels of cement replacement with RHA namely percentages of 0, 5, 10, 15 and 20 by weight. One hundred and twenty cubes were cast (4x3x5x2=120) and tested for compressive strength at 7 and 28 days. Based on the compressive strength values, 1:5 binder-sand ratio was chosen as the appropriate mix proportion to cast cellular masonry blocks for different water-binder ratios namely 0.5 and 0.6 as per SLS 855Part 1:1989. RHA was blended with cement in percentages of 0, 5, 10, 15 and 20 by weight in producing cellular masonry blocks of size 390 x 190 x 200 mm. These were tested for water absorption in addition to compressive strength. The compressive strengths of cellular masonry blocks at 7, 14 and 28 days for 1:5 binder-sand ratio, water-binder ratio 0.5 and 5 per cent cement replaced with RHA were 2.05 N/mm2, 2.24 N/mm2 and 3.37 N/mm2 respectively. Likewise the values for 1:6 binder-sand ratio for water-binder ratio 0.5 and 5 per cent cement replaced with RHA were 1.6 N/mm2, 2.18 N/mm2 and 3.24 N/mm2 respectively. The minimum compressive strength as per SLS 855 Part I: 1989 is 1.2 N/mm2. The water absorption rates for water-binder ratios 0.5 and 0.6 are 9.8 and 10.5 respectively, which are within limits; the allowable limit is 10-15% as per BS EN 1996-1-1. The study concludes that 15 per cent cement replacement level is permissible

Engineer: Journal of the Institution of Engineers, Sri Lanka

River sand is the most widely used fine aggregate in civil engineering constructions in Sri Lanka... more River sand is the most widely used fine aggregate in civil engineering constructions in Sri Lanka. Traditionally river sand is extracted from rivers and streams. In the Jaffna peninsula there are no rivers or streams flowing through the area. Sand deposits in rivers are depleting in Sri Lanka, especially in the Southern region, as the annual demand for sand is very high due to rapid increases in civil constructions. The total demand of sand in Jaffna is met by the supplies of sand from the Southern region. This has led to large scale sand mining in the southern part of the country. As a result, most river banks have been eroded. Therefore, it is necessary to minimize sand mining, which is hazardous to environment.

Engineer: Journal of the Institution of Engineers, Sri Lanka, Dec 31, 2019

Engineer: Journal of the Institution of Engineers, Sri Lanka, 2015

The Social Safeguard Management Programme (SSMP) has become a key component of irrigation related... more The Social Safeguard Management Programme (SSMP) has become a key component of irrigation related rehabilitation projects. This paper reviews a renewed approach to developing SSMP that has been adopted in the rehabilitation of four reservoirs coming under the DSWRPP, where water releases had to be suspended temporarily to enable the rehabilitation. The SSMP has been designed in such a way that livelihood support assistance is provided to 8,344 affected families in the downstream communities. The conduct of Social Impact Assessment and the development of Livelihood Support Assistance (LSA) plans are illustrated. The LSA plan has four sub plans namely Wage Assistance Plan, Alternative Crops Plan, Domestic Water Use Plan and Gender Action Plan. The affected people have contributed to the economy by working in the rehabilitation work and saving foreign exchange by cultivating alternative crops. The paper presents ample evidence of the level of contentment and happiness of the farmers at the end of the programme, they being made responsible for the development and implementation of the LSA plans. The main argument offered in this article is that the programmes to assess and mitigate socioeconomic impacts should primarily take into account the perspectives of the people without exclusively relying on specialists or technocrats.

Engineer: Journal of the Institution of Engineers, Sri Lanka, 2016

This research paper explores the possibility of using indigenous woody plant materials as the rei... more This research paper explores the possibility of using indigenous woody plant materials as the reinforcement for composite members in cement mortar. The objectives of the study are to ascertain the stress-strain relationship and volumetric stability of indigenous woody plant materials with respect to locally adopted seasoning techniques. The survey identified six woody plant materials namely Veval, Una, Tharana, Eraminiya, Kooratiya and Dodanpana, which are worthy of being investigated based on past knowledge. The two locally adopted seasoning techniques investigated in this research are air drying and heat treatment. The specimens subjected to air drying for seasoning record higher tensile strengths than the heat treated, with respect to all six materials investigated. While Dodanpana records the lowest variation in cross sectional area, Tharana, Kooratiya and Una also show relatively high stability in relation to shrinkage. Three out of the six woody plant materials investigated, Kooratiya Tharana and Dodanpana can be recommended as suitable to be used as reinforcements, in terms of tensile strength, cross sectional area stability and length stability. These materials could be utilized for replacing mild steel reinforcements in Reinforced Cement Mortar (RCM) composite members. RCM could be effectively adopted for relatively low stress level applications in rural areas, where the villagers can easily obtain such woody plant materials and season the same using traditional methods.

Engineer: Journal of the Institution of Engineers, Sri Lanka, 2016

The purpose of this study is to select a more effective technique from 'upstream cutoff' and 'gro... more The purpose of this study is to select a more effective technique from 'upstream cutoff' and 'grouting treatment' for the control of seepage through the Vendarasankulum reservoir. Using engineering judgment, empirical and theoretical knowledge, trapezoidal cross sectional dimensions of layers of different soil materials were determined. For example, the cross section at 490m (from left); SC layer on the U/S side slope has widths, 3m and 12m at bund top and bottom respectively; clay layer in the core has widths 12 m and 3 m at the top and bottom respectively. The effective fetch (1.72 km) and thereby the maximum wave height (0.84m) were computed in order to extract values for thicknesses of riprap (0.45 m) and bedding layer (0.30m). Grouting treatment involves clay-cement grouting in the overburden and 6m deep cement grouting in the rock, requiring a total of 296 grout holes. While the estimated cost of construction of the upstream cutoff is SLR 30.3 million, the same for grouting treatment is SLR 11.3 million, indicating the former option would cost 168 percent more. Therefore, grouting treatment is more economical and sufficient, although upstream cutoff could offer better seepage control.

Engineer: Journal of the Institution of Engineers, Sri Lanka, 2006

There are 3 different versions of tile laying techniques adopted in the industry at present and n... more There are 3 different versions of tile laying techniques adopted in the industry at present and no attempt has been made so far to evaluate these techniques and thereby to promote the most desirable technique. Of the three techniques, in the first two, tiles are fixed on to the already hardened bed using cement slurry. These two techniques differ from one another because one uses a rectangular shaped toothed trowel while the other uses the standard mason's trowel to apply the cement slurry. In the case of the third technique, tiles are fixed on to fresh mortar bed after applying a coating of lean cement slurry. Data was collected from 15 sites; five for each technique to determine the cost effectiveness of each technique. Out of the above, 12 sites were considered to evaluate the performance of each technique with respect to quality. The results obtained after the analysis revealed that the third technique which involves fixing of tiles soon after the mortar bed is laid, is the most cost effective since it consumes less cement and sand. The quality of tile laying was assessed in terms of two parameters namely, bondage and level. The above technique is the best with respect to bondage of tiles with the substrate. However, this technique performs poorly when it comes to maintaining the uniformity of levels of individual tiles. This is due to the deformability of fresh mortar bed on which tiles are placed. The tilers who applied this new technique were not entirely conversant with it. Therefore, the results obtained could be further improved by engaging tilers skilled in this technique. If the public and private sector stakeholders' sponsorship is forthcoming this technique can be promoted and personnel to be engaged can be trained so that it can be applied on a mass scale.

Engineer: Journal of the Institution of Engineers, Sri Lanka, 2016

In an effort to ease off the financial burden on contractors, a government policy was enacted on ... more In an effort to ease off the financial burden on contractors, a government policy was enacted on first November 1997, to reduce the existing ten percent penal sum of the performance bond to five percent. There was no overall justification for this decision. The primary aim of this study is to explore the adequacy of indemnity afforded by the penal sum of five percent, for the performance bond used in construction contracts. The sample of the study has been confined to 25 state sector building projects. These projects were either completed with the same contractor with a time extension or with a new contractor after terminating the former. The main contribution of the study is the construction of several confidence intervals for the population mean of 'total loss to the client as a percentage of the contract sum'. The study reveals a more pragmatic and compromising penal sum of seven and half percent when a conducive environment prevails to procure performance bonds. Still contractors do not have cheaper and easier ways of obtaining performance bonds. Further, performance bonds are seldom called on. Hence, the study recommends that the prevailing five percent penal sum remain the same. The study also has highlighted the problems the contractors encounter in procuring performance bonds from bond providers (sureties) such as banks, insurance companies and the Construction Guarantee Fund.

Engineer: Journal of the Institution of Engineers, Sri Lanka, 2016

This paper investigates the many causes of delays in the pre-construction phase of State Sector B... more This paper investigates the many causes of delays in the pre-construction phase of State Sector Building Projects. The investigation was done through a questionnaire based survey that involved Clients, Consultants and Contractors to evaluate the causes of delays. The technique of Relative Importance Index was adopted to rank the causes of delays in a descending order. Based on this evaluation the causes of delays were identified and ranked, and two remedial measures were developed. Firstly, a process diagram for the pre-construction phase was designed in order to establish the systematic process and to represent useful inputs and outputs at various stages of the process. Secondly, a checklist was formulated in an effort to ensure that important actions are taken at the correct stages to minimise the opportunity for delays. Also, the study proposes suitable additions/ amendments to the 'Form of Agreement', an ICTAD publication, and recommends to make the use of these remedial measures mandatory.

Engineer: Journal of the Institution of Engineers, Sri Lanka, 2015

This study focuses on determining important causes of construction delays attributable to contrac... more This study focuses on determining important causes of construction delays attributable to contractors in large construction projects in Sri Lanka and the degree of severity of these causes. The causes of delay have been found based on the perceptions of the engineers working for three state affiliated establishments namely, Department of Buildings (BD), Road Development Authority (RDA) & National Water Supply and Drainage Board (NWSDB).The severity of each cause of delay is measured and represented through a severity index (SI). The causes of delay were determined and ranked in the descending order of severity. According to the findings, Poor project planning & scheduling (SI-82.54) is the most influencing factor causing delays in construction projects. In the descending order of severity, the other causes of delay are Low profit margin (SI-80.28), Inadequate cash flow management (SI-78.31), Handling of too many project sat a given time (SI-75.21), and Incompetence of the key staff (SI-74.93).Spearman rank correlation coefficient was used to determine the degree of agreement on the ranking of severity of causes of delay among the organisations. The highest degree of agreement is between BD &NWSDB (0.77). There exists an intermediate degree of agreement between RDA & NWSDB (0.73) and the lowest is between RDA & BD (0.70).The study finally makes 10 recommendations to mitigate construction delays.

Technology and Investment, 2012

This paper explores the impact of the adoption of Flexible Manufacturing Technology (FMT) on the ... more This paper explores the impact of the adoption of Flexible Manufacturing Technology (FMT) on the Malaysian Manufacturing Industry. The Principal Component Analysis has been adopted to extract the most appropriate underlying dimensions of FMT to use in place of the eight FMT variables owing to the potential multicollinearity. The study has been conducted within FMT intensively adopted 16 three-digit industries that encompass 50 five-digit industries covering the years 2000-2005. The results obtained from the two scenarios, one, including the industry fixed effects dummy variables and the other without these, are contrasted. It is established that the model that included the industry fixed effect dummy variables has a greater explanatory power. The two principal components that account for the greater variation in FMT show positive and moderately significant relationship with PCM. The study provides sufficient evidence to conclude that FMT has a direct and moderately significant relationship with PCM.

Technology and Investment, 2012

This paper examines the impact of the adoption of Flexible Manufacturing Technology (FMT) on the ... more This paper examines the impact of the adoption of Flexible Manufacturing Technology (FMT) on the Technical Efficiency of Malaysia Manufacturing Industry. Owing to the potential multicollinearity, the Principal Component Analysis has been adopted to extract the most appropriate underlying dimensions of FMT in an effort to substitute the eight FMT variables. The study has been conducted within FMT intensively adopted 16 three-digit industries that encompass 50 five-digit industries covering the years 2000-2005. The results obtained from the two situations, one, including the industry fixed effects dummy variables and the other without these, are contrasted. It is found that the model that included the industry fixed effect dummy variables possesses a greater explanatory power. The two principal components that account for the greater variation in FMT show positive and moderately significant relationship with TE. The study concludes with sufficient evidence that FMT has a direct and moderately significant relationship with TE.

Engineer: Journal of the Institution of Engineers, Sri Lanka, 2014

Engineer: Journal of the Institution of Engineers, Sri Lanka, 2014

The main purpose of this study is to identify the significant causes of time overrun in construct... more The main purpose of this study is to identify the significant causes of time overrun in construction phase of building projects handled by the Department of Engineering Services (DOES) of Sabaragamuwa Provincial Council (SPC) and to propose mitigative measures. The preliminary investigation of this research revealed that 80% of the building projects handled by the DOES are not completed within the agreed contract period. The study determines 51 factors causing time overrun in the context of the DOES, which is the basis of the study. The perceptions of clients, consultants and contractors regarding frequency of occurrence and severity of these factors were obtained using questionnaire. Using the indices of frequency, severity and thereby the indices of significance were computed for all the factors. 'Rainy weather', 'poor liquidity of the contractor' and 'inaccurate planning and scheduling of projects are identified by all parties as the most significant factors causing time overrun. According to the views of both clients and consultants, 'contractor related factors' are the most significant causes of time overrun. As for the degree of agreement of perceptions on delay causes. the highest is between clients and consultants (68%) and the lowest between the contractors and clients (50%). Finally, the research makes propositions separately for each party in the contract in order to mitigate the respective contribution towards time overrun

Economic Modelling, 2010

This paper investigates the influence of the adoption of Flexible Manufacturing Technology (FMT) ... more This paper investigates the influence of the adoption of Flexible Manufacturing Technology (FMT) on the Total factor Productivity Growth (TFPG) of Malaysia Manufacturing Industry. The Principal Component Analysis has been adopted to extract the most appropriate underlying dimensions of FMT to use in place of the eight FMT variables owing to the potential multicollinearity. The study has been conducted within FMT intensively adopted 16 three-digit industries that encompass 50 five-digit industries covering the years 2000-2005. The results obtained from the two situations, one, including the industry fixed effects dummy variables and the other without these, are contrasted. It is established that the model that included the industry fixed effect dummy variables has a greater explanatory power. The two principal components that account for the greater variation in FMT show positive and moderately significant relationship with TFPG. The study provides sufficient evidence to conclude that FMT has a direct and moderately significant relationship with TFPG.

British Journal of Applied Science & Technology, 2013

The aim of this study is to test the relevant properties of offshore sand obtained soon after dre... more The aim of this study is to test the relevant properties of offshore sand obtained soon after dredging and to examine the effects on chloride levels of offshore sand when fresh water is drained to simulate average monthly rainfalls. The findings are valid for offshore sand that does not require washing particularly to remove organic matter and other contaminants. As per the results of sieve analysis, grading of the offshore sand is within the limits specified in BS 882:1992. The compressive strength of grade 25 concrete which is the mostly used structural concrete is also within the acceptable limits. The shell content of offshore sand for shells finer than 10 mm and coarser than 5 mm is 6.5 per cent. This is far below the 20 per cent limit specified in BS 882:1992. For grade 25 concrete produced with OPC, an allowable limit of 0.101 per cent by weight of sand was computed for chloride content in offshore sand. The chloride content of offshore sand obtained soon after dredging was 0.04%. Even a rainfall as low as 9.9 mm can reduce the chloride content (range from 0.01 to 0.05) to levels far below the allowable limit (0.101). Rainfalls as high as 581 mm could wash away chlorides almost completely