ICPT - 2021

Permanent URI for this collectionhttp://192.248.9.226/handle/123/20174

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item: Conference-Full-text
A framework for selecting safety treatments for rural roads
(Springer, 2021) Ranawaka, RKTK; Pasindu, HR; Dias, TWKIM; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
Road safety is a vital element of the road’s overall function, which is often neglected in decision-making for road maintenance management. As a result, the safety issues, especially in rural roads, remain without funding to implement the necessary countermeasures. One constraint faced by local authorities is the lack of analysis tools to select appropriate safety treatmentswithin the available budget. This study presents a methodology to logically determine the safety treatment criteria for a selected road to increase the safety performance at project level. The decisions regarding the safety treatments are taken based on a linear programming model which optimizes the safety performance of the selected road. Cumulative Safety Index (CSI) represents the safety performance of the road, which is determined based on the prevailing issues on that road. The model comprises the objective function by which maximizes the safety performance of the selected road concerning the number of prevailing safety issue types. This model is used to identify the optimal safety treatment scheme for the road chosen, ensuring prevailing safety issues of the road are effectively addressed. The objective function consists of the Initial CSI of the selected road and the safety improvement after treating relevant issue type coupled with a binary decision variable. This model can also be considered an input to road asset management systems where multi-objective optimization (MOO) models maximize the network pavement condition and maximize overall network safety performance.
item: Conference-Full-text
Automatic pavement crack rating for network-level pavement management system
(Springer, 2021) Tan, JY; Nguyen, T; Kapilan, S; Nyunt, TT; Lim, YH; Leong, YF; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
Cracking is one of the important distresses that can be used to trigger pavement maintenance treatments. Traditional crack rating is commonly based on the Pavement Condition Index (PCI) approach involving time-consuming visual inspection and manual classification processes. The emergence of automatic and high-speed laser imaging devices significantly improves the efficiency and productivity of pavement crack data collection but it requires suitablemethods and concepts for automatic crack ratings. This paper discusses the development of an automatic pavement crack rating using crack data collected from a high speed 3D sensor. Two levels of crack ratings are proposed: Level 1 provides detailed crack information including cracking extent, crack types and severity, and Level 2 is a macro-indicator of general/overall cracking extent on a pavement section of 10 m length. The method and concept were developed and tested initially for Singapore expressway network under the effort of the Land Transport Authority (LTA) of Singapore to integrate crack data into the pavement management system (PMS).
item: Conference-Full-text
Evaluation of the structural condition of composite pavement
(Springer, 2021) Budiman, E; Setiadji, BH; Wardani, SPR; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
One of the road tolls at the borderline of Jakarta, the capital of Indonesia, i.e., Tangerang-Merak toll road, was found in a damaged condition in several locations. The toll’s pavement structure comprises an asphalt layer (blacktopping) over a concrete slab (or a composite structure). An evaluation is required to find out the last condition of the pavement to propose the remedy for the problem. An eight-step evaluation was conducted systematically in this study, and the 1993 AASHTO method was the method used to analyze the results. The first step was to conduct traffic analysis by calculating ADT from toll gate transaction data validated with CCTV data, while vehicle axle loads were measured by static load surveys to calculate the vehicle equivalent factor.Another analysis of the pavement’s structural conditionwas conducted using backcalculation analysis using FWD deflection data to produce the moduli of subgrade reaction and the elastic modulus of the concrete pavement. The analysis showed that several locations of the toll road suffered a medium to severe deterioration as indicated by high deflection values. This fact was also supported by the findings that the pavement system’s remaining life is 22% on average. Two recommendations were made by implementing 7.12 in. or 18 cm overlay thickness on the in-service pavement for road segments with good prediction of moduli, and 2 in. or 5 cm repairing treatment to strengthen the existing pavement may be considered as planned stage of construction for the rest. Before the overlay and treatments were conducted, various repairs were taken place on the damaged spots along the road segment.
item: Conference-Full-text
Feasibility study on pavement rutting evaluation method based on smartphone
(Springer, 2021) Zhang, JX; Wang, PR; Cao, DD; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
With the continuous increase of constructions in highway, road maintenance has become more and more important. Thus, it is of great significance to develop the rapid, intelligent and real-time detection technologies for road surface conditions. This paper used the self-developed driving data acquisitionAPP to collect the vibration acceleration data during driving, and carried out the feasibility study on the evaluation method of pavement rutting using smartphones. Firstly, the collected vibration acceleration data are de-noised, and the vibration characteristics under different working conditions are analyzed. Secondly, seven time-domain vibration acceleration indexes with high correlation with pavement rutting are extracted, and the dimensions of seven primary indexes are reduced to two independent principal components by principal component analysis. Finally, the rutting evaluation model based on convolutional neural network is established and compared with the results of back propagation neural network and multilayer perceptron neural network. The results show that the average relative error of the rutting evaluation model based on the convolutional neural network is 16.6%, which is lower than the other twomodels. It indicates that the pavement rutting can be evaluated satisfactorily by smartphones. In addition, this paper divided the evaluation results of rutting into four grades (Excellent, Good, Medium and Poor) and displayed them in different colors on the map. This study is of great significance to improve the level of intelligent detection of road rutting and road maintenance management.
item: Conference-Full-text
Feasible treatment selection for routine maintenance of flexible pavement sing fuzzy logic expert system
(Springer, 2021) Kumar, R; Suman, SK; Singh, A; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
Pavement maintenance management system motivates to provide a scientific tool for maintenance and rehabilitation of roads pavement at desired serviceability levels. In view of the fund’s constraints and the need for judicious spending of available resources, the maintenance planning and budgeting are required to be done based on scientific methods. Unfortunately, the current maintenance practices are ad-hoc and subjective in nature. Pavement condition responsive maintenance is very useful for judicious disbursement of maintenance funds. The objective of this paper is to select a feasible treatment for routine maintenance based on pavement condition parameters of flexible pavement using Fuzzy Logic Expert System (FLES). Six different national highways have been selected to provide the maintenance based on the PCI, traffic volume, pavement age, precipitation, temperature and budget. FLES offers a convenient tool to better represent the uncertainty involved in pavement condition rating and assessment. The pavement maintenance treatment needs are generally determined based on the results of visual inspection, which in most of the cases does not give an adequate representation of pavement condition. Treatment selection FLES model has considered anticipated distresses-based condition index, anticipated traffic, and prevailing climate, age of the pavement and budget for treatments. Model predicts treatment types based upon their expected life. The triangular membership function for all the parameter is considered and analyzed with sufficient number of fuzzy rules as suggested by the maintenance engineers. The predicted result was compared with the twenty-five maintenance engineer’s responses, which shows homological results. Hence, this approach may provide an appropriate and economically viable maintenance treatment.
item: Conference-Full-text
Functional condition evaluation of airfield pavements using automated road survey system—a case study of a small sized airport
(Springer, 2021) Kumar, P; Sharma, M; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
Airports are vital national resources. Airfield Pavements within an airport represents a large capital investment in infrastructural development made by a country. Timely and appropriate maintenance and rehabilitation of such in-service facilities are essential to provide an all-weather surface for safe and regular operations of the aircraft. Pavement maintenance is done based on functional and structural pavement condition evaluation. This paper presents a case study dealing with functional evaluation of airfield pavements of a small sized airport in India. The considered airport consists of two runway, seven link taxiways, three apron areas and an isolation bay with different surface types. Present paper reports the methodology adopted for the functional condition evaluation of the airfield pavements with help of Automated Road Survey System. Further, the evaluated pavement condition was quantified in terms of Pavement Condition Index (PCI) as per the ASTM D5340 with help of PAVER and GIS based software. GIS was used for preparing inventory database and basemaps for the concerned pavementswhich were then used in PAVER software for determining the PCI. The airfield pavement network within the airport was divided into a four-level hierarchy consisting of the network, branch, section and sample. The obtained PCI rating shows that the overall condition of the airfield pavements within the considered airport is satisfactory to good, however some of the areas have distresses that needs to be repaired by localized maintenance.
item: Conference-Full-text
Side friction as a cause of poor pavement maintenance in India—a study using terrestrial laser scanner data
(Springer, 2021) Singh, SG; Kumar, SV; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
Side friction is a peculiar characteristic that can be seen mainly in urban roads of India where the part of carriageway is utilized for activities like on-street parking, encroachment, etc. Though there are many studies on speed and capacity reduction due to side friction, however studies on carriageway width reduction are very limited. Hence an attempt has been made to measure the carriageway width loss due to side friction activities using the terrestrial laser scanner data and analyze the causes of such activities. Two locations with a stretch of about 50 m. each in Vellore, India was taken as study stretches and laser scanning was carried out using the Leica BLK 360 laser scanner. The total carriageway width and effective carriageway width were measured accurately using the point cloud data. It was found that, in one of the locations, almost one lane was occupied by on-street parking of vehicles. Aggregates were just poured over it along the lane and because of that vehicles were not moving on the lane. Hence it encourages illegal on-street parking of vehicles at that location as the lane was not utilized for vehicle movement. Similarly, at other location also, pavement maintenance was not carried out and thus a strip of sand particles along the shoulder-side lane was found which also eventually led to on-street parking as the lane was not utilized for vehicle movement. Thus, the results clearly says that lack of pavement maintenance is one of the major causes for side friction activities in India.
item: Conference-Full-text
Comparison of flexible airfield pavement designs using faarfield v1.42 and apsds 5.0
(Springer, 2021) Chai, G; Bell, P; McNabb, K; Wardle, L; Oh, E; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
A case study has been carried out to compare the design of airfield pavements for a major airport using FAARFIELD v1.32 and APSDS 5.0. For the aircraft departure data used in the study, the pavement analysis shows that the APSDS 5.0 design method yielded pavement structure thicknesses that are nearly the same as FAARFIELD v1.32 for CBR greater than 10%. An adjustment factor kc is required for APSDS design thickness to produce designs that are consistent with FAARFIELD for CBR less than 10%. In May 2017, FAA developed new subgrade failure models for flexible pavements in FAARFIELD v1.41 using the full-scale traffic test data collected at the NAPTF for Test Sections in Construction Cycles CC3 and CC5. FAARFIELD v1.41 was subsequently updated and evolved to version 1.42 in September 2017. In this paper, a comparison is carried out using the latest version of FAARFIELD v1.42 to examine if the new subgrade deformation models compute the design thicknesses that are compatible with that generated by APSDS 5. For the Boeing 737-800 (Code C) and 777-300ER (Code E) aircrafts spectrum and 100,000 movements analyzed in the study, the new subgrade failure models developed for the latest version of FAARFIELD generate the flexible pavement thicknesses that are not significantly difference from that of APSDS 5.0 for subgrade CBR ≥5%. The new failure model in FAARFIELD v1.42 produces flexible design thicknesses that differ less from APSDS 5.0 than FAARFIELD v1.32. The design thicknesses are more consistent for B737-800 with 2 wheels configuration. However, the differences are observed to be larger for CBR ≤5% when modelled with B777-300ER having 6 wheels configuration. The differences in the design thickness are attributed to the different coefficients adopted in the subgrade failure models in the design software.
item: Conference-Full-text
Influence of coarse aggregate size and type on the design thickness of rigid pavements for Indian conditions
(Springer, 2021) Bellary, A; Suresha, SN; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
The pavement quality concrete (PQC) is used in the construction of rigid pavements, commonly called concrete pavements. The coarse aggregates (CA) are the major constituents of the PQC mix, which influence the strength of the PQC mix. The strength of the PQCmix used in the construction of rigid pavements is one of the major factors that govern the design thickness of these pavements. In this study, an attempt has been made to characterize the influence of CA size and type on strength characteristics of the PQC mix experimentally. The crushed basalt and granitic CA are used in the preparation of the PQC mix. Also, three different nominal maximum aggregate size (NMAS) 19, 26.5 and 31.5 mm, are selected based on the IRC 44: 2017 guidelines. The experimental results are given as input in EverFE 2.24 software for determining the safe design thickness of rigid pavement over the design period. It is concluded that the safe design thickness of the PQC mix prepared using basaltic CA is comparatively lower than the PQC mix prepared using granitic CA for the same NMAS. Also, the safe design thickness of concrete pavement increased with an increase in NMAS irrespective of CA type. Thus, it is suggested to use stronger CA with lower NMAS based on the availability at the site.
item: Conference-Full-text
investigating impact of boundary layer in pervious concrete
(Springer, 2021) Sajeevan, M; Ahilash, N; Subramaniam, DN; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
Pervious concrete is a green concrete because of its environmental benefits including reduced carbon footprint. However, industrial application of pervious concrete is limited by uncertainty of its mechanical properties. While porosity plays an important role in mechanical properties and understanding on porosity distribution and characteristics is essential in optimising design of pervious concrete. Image analysis is a modern tool which could employ different analyses techniques and significantly reduce error than in conventional methods of analysing porosity. This study aims to analyse distribution of porosity in pervious concrete, using image analyses tools. Cubes were cast, cores were obtained, and images of the surfaces were painted and photographed. Image was converted to binary and analysed and total porosity of cubes were obtained. A small layer in the top and bottom have high porosity than total porosity and between those layers the porosity,which is lower than total porosity, is called effective porosity. Therefore, the top and bottom boundary layers were analysed with design parameters. Top boundary layer of a concrete cube is 4.7 mm and it does not depend on design parameters. The bottom boundary layer of the concrete cube increases with the aggregate to cement ratio and decreases with applied compaction energy. For blows more than 45, the bottom boundary layer does not significantly change. Minimum required number of blows for the 1st layer of the cube to get optimum bottom boundary layer is 10 for all Aggregate to cement ratio (A/C) except for design with A/C of 2.5.
item: Conference-Full-text
Laboratory investigations on lateritic soil stabilized with rbi grade 81, coconut fiber and aggregates
(Springer, 2021) Chethan, BA; Shankar, AUR; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
Soil stabilization is an excellent old technique adopted to improve the properties of any weak soil. In the recent past, many chemical stabilizers came to the market. In this study, a commercial stabilizer-RBI Grade 81’s (dosage 2–8%) potential to improve lateritic soil properties was investigated. At 6% RBI Grade 81 dosage, the effect of reinforcement was evaluated by using 0.5 and 1.0% coconut fibers. Strength improvement of 6% RBI Grade 81 stabilized soil admixed with <12.5 mm size aggregates (5, 10, and 15%) was studied to know the effect of granular layer demolition waste incorporation. CBR and UCS tests were used for strength evaluation. Considerable improvement in mix strength was observed above 6% RBI Grade 81 dosage on 28 curing days for the soil incorporated with fibers and aggregates. A linear fit was established between UCS and soaked CBR, which shows a high correlation (>0.9), and Prob > F is <0.06 depicting high reliability for the estimation of soaked CBR from UCS. Further, fatigue and durability tests were carried out to understand stabilized soil’s behavior under dynamic load application and performance during monsoon to simulate the submerged condition of the pavement in dense rainfall areas (>3500 mm). Stabilized lateritic soil mixes sustained freeze–thaw cycles effectively with weight loss of <14%. However, even at an 8% RBI Grade 81 dosage, the mix has not satisfied the wetting–drying test requirement. Stabilized soil blends showed excellent fatigue performance under repeated loads. The 6% RBI Grade 81 treated soil mixes can be used for modified subgrade.
item: Conference-Full-text
Monotonic loading test to investigate the benefits of composite geogrids for subgrade improvement
(Springer, 2021) Wimalasena, K; Gallage, C; Jayalath, C; Churchill, J; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
The presence of weak subgrades is one of the greatest challenges in constructing road pavements. Conventionally, techniques such as refiling with suitable material and soil stabilisation are considered to improve subgrade condition, ignoring the additional project cost. However, geogrids have gained popularity as economical, expedite and sustainable subgrade improvement techniques over recent times. Although many studies have been conducted to assess the suitability of biaxial geogrids, limited studies have been performed to check the suitability of composite geogrids for subgrade improvement, despite assuming that composite geogrids extend additional benefits. In this study, two model tests: one unreinforced and one composite geogrid reinforced, were constructed in a steel box with length, width, and height of 1 m, 1 m and 1.2 m, respectively. The subgrade was prepared to a thickness of 500 mm, achieving CBR 2.5% bearing capacity. A granular layer of 200 mm was constructed on top of the subgrade achieving 100% degree of compaction frommaximum dry density. In the reinforced section, composite geogrid was placed at the base subgrade interface. Both model sections were subjected to a monotonic load at a rate of 1 mm/min, applied on the top surface of the granular layer through a circular plate of 200 mm diameter, until the occurrence of ultimate failure. Results demonstrate that reinforcing the weak subgrade by a composite geogrid has increased the ultimate bearing capacity by 53%. In addition, the overall section modulus of the composite geogrid reinforced section is higher than the modulus of the unreinforced section.
item: Conference-Full-text
Numerical simulation of differential settlement resistance for reinforced joint between new and existing pavement with road mesh steel wire mesh
(Springer, 2021) Zha, XD; Liu, HJ; Zhu, JH; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
In order to analyze the ability of longitudinal cracking resistance due to differential settlement between new and existing subgrade in the joint between new and existing pavement reinforced by RoadMesh steel wire mesh, and relying on the existing road widening project, three kinds of layer location reinforcement schemes were selected, which are between surface layers (Scheme I), between surface layer and base (Scheme II) as well as between base and subbase (Scheme III). The maximum void value of 10 mm due to differential settlement was set on the surface of new subgrade under the outer edge of new shoulder. The three-dimensional finite element numerical models were established to carry out the comparative analysis of mechanical responses of widening asphalt pavement structure for different reinforced layer locations. The results show that the peak value of maximum tensile stress and the deflection value of doublewheel gap center in pavement surface can be used as the main control indexes for differential settlement resistance. All the orders of simulation results of the two indexes under each scheme are Scheme I < Scheme II < Scheme III < Unreinforced. The simulation results of the two indexes in Scheme I are 53.4% and 60.6% lower than those of the unreinforced scheme respectively. It indicates that the joint between new and existing pavement reinforced by the RoadMesh can effectively improve the differential settlement resistance of widening asphalt pavement structure. The closer the reinforced layer location is to the pavement surface, the more significant the reinforcement effect is, so the optimum reinforcement layer location is between surface layers.
item: Conference-Full-text
Optimising pervious concrete design with partial replacement of cement with fly ash
(Springer, 2021) Ahilash, N; Sajeevan, M; Subramaniam, DN; Rajakulendran, M; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
Pervious concrete is a light-weight concrete that does not contain fine aggregates (sand) and of enhanced porosity compared to conventional concrete. Partial replacement of cement paste bywastematerial, reduces environmental impact both by reducing carbon footprint of cement usage and usage of waste material. Partial replacement of cement by fly ash in conventional concrete is an accepted substitution that also significantly enhance mechanical properties. However, porous concrete being different from conventional concrete, studies are scarce in applicability of such replacements in porous concrete. This study aims to optimise partial replacement of cement by fly ash in porous concrete. By changing the aggregate to cement ratio (A/C) and water cement ratio (W/C) mix designs were formulated, cubes were cast and slump and compressive strength of fresh concrete were monitored. Having obtained highest strength of A/C of 2.5 cubes were cast with varying W/C ratio (0.3, 0.35, 0.4 and 0.45) and the percentage of replacement of cement by fly ash (5, 10, 15 and 20%). Replacement of 10% was observed to be optimum replacement while higher theW/Cwas advantageous for compressive strength. However, for porous concrete the slump of the fresh concrete should be below 15 mm. Therefore, the optimum W/C was 0.3. Finally, the mix design with 2.5 Aggregate to cement ratio, 0.3 water to cement ratio and 10% replacement of cement by fly ash gives 15.22 MPa (95% CI 14.8–15.6 MPa) strength. It is 13% extra strength than using 100% cement for binder.
item: Conference-Full-text
A comparative investigation on the effectiveness of awax and a resin based curing compound as an alternate of water curing for concrete pavement slab
(Springer, 2021) Goel, P; Kumar, R; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
In this study, the effectiveness of two easily available concrete curing compounds in the Indian construction Industry namely; wax and synthetic resinbased, in comparison with water cured cubes and beams specimens of a paving concrete of 39 MPa compressive strength and 4.5 MPa flexural strength at 28-day has been reported. The concrete specimens were cast and kept for curing under different conditions such as in water, in the sunlight, and under the sunshade. Two coats of curing compounds as per the manufacturer’s instruction were applied on the surfaces of the concrete specimens and put in the sunlight and under the sunshade. The compressive and the flexural strength in comparison with water cured concrete specimens were evaluated. The study has shown 12% lower compressive strength and about 7% lower flexural strength for concrete samples cured with resin-based curing compound than the water cured samples. The study also indicates a reduction in compressive and flexural strengths of about 33% and 11%, respectively for waxbased curing compound. Finally, the study shows an upper hand for the resin-based curing compound, however, neither of them has shown potential as an alternate for the conventional water curing.
item: Conference-Full-text
Applicability of gneiss based mineral aggregates for the use in high friction surface treatment in terms of polishing characteristics
(Springer, 2021) Thenuwara, HV; Buddhi, PHGH; Pasindu, HR; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
Speed and safety management of highways plays a prominent role in ensuring road user safety, especially of the vulnerable categories. Pavement Friction Management (PFM) is being considered as the best possible option in developing the road infrastructure over the other prevalent strategies, with the focus of improving user safety. High Friction Surface Treatment (HFST) is widely being used as a remedial measure to improve the friction and texture retention capacity of the wearing course, as it provides economical and sustainable solutions in upgrading the pavement performance in both as an urgent response and in the long run as well. As an urgent remedial intervention, HFST can be incorporated in the national practice of safety management in Sri Lanka, to address the concerns over the escalating numbers of grievous highway crashes. In place of the most commonly used high skid resistant aggregates, gneiss-based mineral aggregate can be a viable alternative since it delivers similar functionality to that of granites. The study examines the polishing characteristics of widely used gneiss-based roadstones in the country through laboratory experiments involving the Polish Stone Value (PSV) test. Both qualitative and quantitative analyses of the specified physical and mechanical laboratory testing are conducted to evaluate the applicability of gneiss-based mineral aggregates in the use of HFST as an alternative skid-resistant roadstone in terms of their polishing behavior.
item: Conference-Full-text
Chemical properties of modified bitumen incorporating coconut char
(Springer, 2021) Mamat, R; Hainin, MR; Hassan, NA; Warid, MNM; Satar, MKIM; Rahman, NAA; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
Agriculture waste have many advantages such as high specific strength and modulus, low density, renewable nature, biodegradability and absence of health hazards. This advantage is good for construction industry because it can improve the properties of the composites. The coconut fruits contain 40% coconut husk, 30% fiber and 30% dust, consisted of flesh, shell and fiber and chemical composition such as cellulose, lignin, charcoal, acid and potassium. The advantages of coconut shell are strong, rigid and lightweight material, very economical as large amounts are available as agricultural waste material and environmentally friendly. This paper presents the performance of modified binder incorporating coconut char in terms of chemical properties. Fourier Transform Infrared Test (FTIR), Particle Size Analyzer Test (LPSA) and Elemental Analyzer Test (EA) were used to analyze the chemical properties on modified binder. Based on the findings, the increased content of char affects the performance of bitumen significantly, as the bitumen maintains stability and homogenous state even though placed in high temperature condition. The testing result value of FTIR and LPSA are increased with the increased content of coconut char. Based on the results, the modified mixture has the higher chemical components and porosity compared to original bitumen and coconut shell because of the modification.
item: Conference-Full-text
Comparative assessment of cmsdbc and hmsdbc competency
(Springer, 2021) Prakash, G; Suman, SK; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
Over ninety percent of the total road network in India, including the airfield pavements, are flexible pavements with black-top surfaces. The construction of wearing and binder courses of a flexible pavement require high energy consumption during heating of bitumen and aggregate, with consequent giant emission of greenhouse gases during the preparation of hot-mixed bituminous mixtures. Earlier, in flexible pavements, the use of bitumen emulsion was restricted to only spray applications and as dust palliatives, but over the years, with the development of new types, grades, specifications, and availability of improved construction equipment and practices, emulsion-based cold mix technology offers a wide range of solutions. Judicial selection and appropriate use of these technologies can yield significant economic benefits, environmental benefits, and energy security as far as construction and maintenance of roads are concerned. Hence, this paper aimed to compare the strength, durability, and performance of a cold mix semi-dense bituminous concrete (CMSDBC) and hot mix semi-dense bituminous concrete (HMSDBC) pertaining to competency. Materials for the preparation of representative samples are coarse aggregate, fine aggregate, and cement as a filler, in suitable proportions mixed with bitumen or slow-setting cationic bitumen emulsion (where applicable). Tests like Marshall stability, Indirect tensile strength, moisture susceptibility, and rut depth using wheel tracker device were carried out according to standard guidelines. The results showed that CMSDBC yielded significant values, which are comparable with HMSDBC. It infers that CMSDBC is capable to be exercised in the practice for low traffic, low rainfall, moderate and cold climate regions.
item: Conference-Full-text
A brief review: application of recycled polyethylene terephthalate as a modifier for asphalt binder
(Springer, 2021) Zair, MMB; Jakarni, FM; Muniandy, R; Hassim, S; Ansari, AH; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
The management of the waste materials produced on the earth is one of the highly substantial environmental issues. Hence, the increasing usage of plastic every year is one of the concerns across the entirety of theworld. The limiting landfill conditions and higher production of the waste plastic materials stress the researcher to manage it alternatively. Conversely, the growing number of heavy vehicles on roads cause road distress to asphalt pavements that contain pure asphalt binders that are insufficiently resistant. Civil engineers and scientists have attempted to address such issues by enhancing the performance of asphalt pavement via modification of asphalt binders’ properties. This paper summarized the possible utilization of waste polyethene terephthalate (PET) for binder modification. It has been evaluated that the PET can significantly improve the binder properties. The chemical modified PET showed better performance in term of physical and rheological properties. In addition, the compatibility of PET with binder has been highlighted with modified chemical structures and viamorphological assessment of modified binder. In addition to solving landfilling issues of waste PET plastic, such recycling approaches generated in these studies can also be used by asphalt researchers to explore future avenues of improvement for the characterization of asphalt binder as a paving material.
item: Conference-Full-text
A review on utilization of c & dwaste for road and pavement construction in the international context and applicability of the findings to Sri Lanka
(Springer, 2021) Arandara, KP; Priyadarshana, ST; Paranavithana, GN; Dissanayake, R; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
In this paper, the utilization ofC&D(Construction and Demolition)waste for roads and pavements construction is reviewed in the international context. Further, the results are assessed to see the relevance to Sri Lanka. The relevant references gathered from the databases are referred to this study. The different countries and regions including Asia, Australia, Middle-East, Europe, and the USA, are covered with 67 papers. Those references are critically reviewed by applying PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) methodology and key C & D waste types utilized for roads and pavements construction are found out. The paper discusses Recycled Concrete Aggregates (RCA), Crushed Clay Bricks (CCB), and Recycled Asphalt Pavement (RAP) as the C & D materials that commonly are used for roads and pavements construction. Also, policies, laws, regulations, and procedures adopted in multiple countries, applicable to the C & D waste sector are discussed in the paper. The findings are evaluated in the latter part of the paper and proposed applicability/rationales to Sri Lanka are examined simultaneously. The authors conclude that the specified three types of CDW based recycled materials could be utilized across the cross-section of roads and pavements through effective methods and applications in several counties and the same approach is applicable in Sri Lanka also. This study confirms that very significant policy support in terms utilization of CDWis evident in most countries and the particular learnings could be applied in Sri Lanka to improve the current state appropriately.

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