ICCEA-2019

Permanent URI for this collectionhttp://192.248.9.226/handle/123/16243

The first conference of an event will be held every two years at the Department of Civil Engineering, University of Moratuwa. This International Conference will see the participation of many world-recognized researchers as keynote speakers with a total of 16 keynote speeches scheduled over this two-day event as the keynote addresses of general sessions and special sessions. A rigorous refereeing process has finally resulted in accepting a total of 53 research papers for presentation. For this event, there will be participation by many undergraduates, not only from University of Moratuwa, but also from all the state funded engineering faculties of other universities in Sri Lanka. With most of the courses having full Washington Accord based international accreditation, it would be an ideal opportunity for the undergraduates to meet world renowned researchers from all continents to make fresh contacts that could lead to further research collaborations. We also have the active involvement of many postgraduates reading for M.Sc. and Ph.D.

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Now showing 1 - 20 of 47

item: Conference-Abstract
Three storied terrace houses with an insulated rooftop for tropical climatic conditions
(2019) Madurangi, MMN; Jayasinghe, MTR
With the growing population, there can be seen many developments in the construction field in recent times. People tend to move to the city areas seeking more facilities. However, this has been very difficult due to the high cost of land and construction. Although high-rise residential buildings (apartments) may seem to be a good solution, being an Asian country, most of the middle-class people are reluctant to live in these apartments due to cultural and social problems related to congested life. Therefore, to maximize the effective use of urban and suburban land, while providing private garden space for each house, a three storied terraced housing with an insulated rooftop that will allow the creation of a garden at rooftop level will be a winning option. The main advantage of such terrace housing is that it is ability to satisfy all the relevant building regulations applicable to create liveable houses with a land area of less than 100m2 per house (or less than 4 perch). Thus, when the land prices are very high, still it is possible to keep the overall costs lower since only a relatively smaller land area is now required to have a comfortably large house with a roof top garden. The roof top garden can allow regaining the land lost for the footprint of the house and hence can be considered as an attractive option. In this paper, the desirable concepts that can be followed to create thermally comfortable free running occupied spaces is described by considering the salient points of a warm humid tropical climates with low diurnal temperature variations. The various passive features that can be incorporated to various types of terrace housing also have been discussed in detail. Since Sri Lanka is having many variations of tropical climatic conditions varying from warm wet, warm dry and tropical uplands, such a development could provide a representative sample of possibilities that could occur in the tropical belt of the world in counties located on either side of the equator
item: Conference-Abstract
Low cycle fatigue behaviouir of steel/ CFRP composite exposed to loads with constant amplitude.
(2019) Abeygunasekera, S; Gamage, JCPH; Fawzia, S
This paper aims to investigate the fatigue performance of CFRP (Carbon Fibre Reinforced Polymer) bonded steel plate under the three point flexural fatigue. CFRP (Carbon Fibre Reinforced Polymer) bonded steel plate subjected to low cycle fatigue (LCF) to estimate and compare fatigue strength gain with respect to un-strength steel structures. Normal modulus (240 GPa) unidirectional CFRPs were used. Two test series were performed in this test series. A constant loads amplitudes cyclic load is applied on specimens with 2 kN magnitudes and 5 Hz frequency. The Coffin-Manson relation was used to explain the theoretical behaviour of LCF cycles. CFRP strengthened steel indicated a significant improvement in the fatigue life. This retrofitting technique reported significant fatigue strength gain; in the range between 26.8 % and 36.52 %.
item: Conference-Abstract
Innovative reusable lightweight cement blocks
(2019) Mahaarachchi, TN; Perera, SVTJ
The cement blocks are a prefabricated material mainly used to build masonry walls in construction industry. Self-weight of units, workmanship and construction time are key factors affecting the masonry wall construction. The constructing of walls, ensure that the cement blocks are properly aligned with one another and need the skilled and highly paid masons for these masonry works. Considering these facts, the interlocking block masonry offer great advantage in masonry construction. The main feature of this interlocking block system is elimination of mortar layer with the tongue and groove method of the interlocking block. The demand of natural sand in the construction industry has increased due to the reduction of sources and an increase in price. Although, the self-weight of the structure can be reduced by introducing the hollow nature for the masonry blocks and also cost of the construction materials can be reduced due to the reduction of volume of the cement block. The goal in any interlocking system is to ensure efficient construction formation with well aligned masonry structures without skilled masons. Therefore, construction cost can be reduced due to the low skilled workers. Furthermore, the interlocking nature of these innovative blocks can be used for the reusable block. This paper presents an experimental investigation was carried out to introduce a new shape of cement block with interlocking behaviour for masonry wall construction, to fulfil the above-mentioned requirements. The interlocking hollow blocks developed were 390mm × 200mm × 190mm in size with a weight of 21.05 kg. The experimental investigation has shown that average compressive strength of block was 3.25N/mm2 and wall panel strength was 0.93N/mm2, therefore it can be used for load bearing masonry walls. It was also observed the innovative block is economical than conventional blocks.
item: Conference-Abstract
Rapidly constructed two storey thermally comfortable houses for tropical climates with light weight loadbearing concrete panels
(2019) Eric, TB; Gunawardana, SGW; Hasalanka, HHH; Jayasinghe, MTR; Damruwan, HGH
Apartments in tall buildings are often promoted as a solution to rapid urban migration that is happening in the world. However, all the apartment houses that have been undertaken in many parts of the world in large cities have not resulted in desirable results all the time. Therefore, it would be prudent to have high-density developments on small blocks of land with detached or semi-attached housing. Such high-density developments will be a special challenge in tropical climates when the urban heat island effects are considered since a high density of houses can often lead to lack of green cover, and hence to have somewhat higher temperatures than the averages predicted for that locality. The other biggest challenge that is faced in countries with tropical climatic conditions is the extensive use of natural resources based walling materials like fired clay bricks, concrete blocks, etc.; this practice has led to over-exploitation of natural resources and hence it is prudent to explore the possibility of using alternative sources that will use much less amount of natural resources. In this context, converting various types of waste materials to a useful building material will also play a major role. One such material is the lightweight concrete panels produced to have 70% of the volume as air using recycled already used Expanded Poly-Styrene (EPS) panels manufactured in modular form with the dimensions of 0.6 m of length, 2.4 m of height and in thicknesses of 75 mm, 100 mm, 150 mm, etc. The use of panels instead of individual small units will allow rapid construction of a house, and it is shown that it is possible to complete one such house having about 200 m2 with a rooftop terrace in less than 30 working days by employing 6 Nos of semi-skilled workers. In a detailed study carried out on with the tropical climatic conditions prevailing in Sri Lanka as a case study, it is shown that there are so many strategies that can be very effectively used to make such houses extremely thermally comfortable while almost eliminating the heat island effects even if a high density has been achieved with individual blocks as small as 200 m2. The research paper is intended to describe all these aspects by taking an actual two storey house with roof terrace constructed in Sri Lanka in the wet zone.
item: Conference-Abstract
Bond performance of carbon fiber reinforced polymer (CFRP) strengthened reinforced concrete curved beams
(2019) Kahandawa Arachchia, KADYT; Gamagea, JCPH; Chandrathilakea, ERK
The concept of using Fiber reinforced polymer composites for strengthening of concrete structures is one of the trending research areas in the civil engineering industry. Although the use of Near Surface Mounted (NSM) CFRP strips for strengthening of straight beams is widely held in the industry, the evaluation of applicability of CFRP strips on horizontally loaded curved beams is an important aspect. The flexure performance of NSM CFRP strips for out-of-plane bending and the effect of end anchorages to resist the bonding failure using CFRP U-wraps was observed in this series of experiments. A total number of 8 beams of 2000 mm and 4000 mm curvature were tested with one set of control beams and one set of beams strengthened with NSM CFRP strips with end anchors. The test results indicated 10% - 35% increase in flexural strength for the beams with end anchorages.
item: Conference-Abstract
An Investigation into the flexural behaviour of horizontally curved beams strengthened with NSM CFRP laminates
(2019) Kajanan, S; Chandrathilaka, ERK; Gamage, JCPH
An experimental program was carried out to investigate the flexural behavior of Carbon Fibre Reinforced Polymer (CFRP) strengthened reinforced concrete curved beams using the Near Surface Mounted technique (NSM). Seven curved beams were tested, and three of them were taken as control beams without having CFRP. Four-point bending test was used to evaluate the performance in out of plane bending. CFRP strengthened beams showed a significant increase in the ultimate load by almost 23% and 10% for the retrofitted beams with 2000 mm and 4000 mm curvature beam respectively compared to the control beams.
item: Conference-Abstract
Thermal performance of aerated concrete block
(2019) Ranasinghe, RMGB; Jayasinghe, C
The ever-increasing demand for housing and other types of buildings results in heavy utilization of construction materials. Such a growing demand causes an over-exploitation of natural resources in the material manufacturing process. Therefore, various researchers have attempted to develop alternative building materials. Aerated concrete block (ACB) is one such alternative, that could be used as a walling material. Although the strength and durability properties of ACB were established, the building performance of this alternative walling material has not been studied in detail. The research presented in this paper covers an assessment of thermal performance of a wall constructed with ACB and compared that with a reference conventional material which is Cement sand block (CSB). The research is based on an experimental programme carried out with physical models constructed out of ACB and CSB. The thermal performance of physical models was monitored over a period. With the aim of extending the results to a wider range of applications, a computer simulation was carried out and validated with the experimental results. The thermal performance of ACB was found to be better with an indoor temperature reduction in the range of 4C during the peak temperature zone than the conventional CSB. Better thermal performance will result in a saving in the operational energy of a building constructed with ACB and hence improving sustainability.
item: Conference-Abstract
Study on concrete with manufactured sand
(2019) Tharshigan, T; Kajaharan, T; Baskaran, K
Concrete is the most widely used and versatile material of construction all over the world. All these years, natural river sand is being used as fine aggregate, by the Sri Lankan concrete industry. However, the amount of river sand available is inadequate to cater the current demand. This paper is about the application of manufactured sand in concrete as a fine aggregate instead of natural river sand. This study was carried out to compare the compressive strength and durability properties of concrete made up of manufactured sand and river sand as fine aggregates. Also, the physical properties of river sand and manufactured sand were compared. Use of fly ash as a partial replacement material for cement in concrete was also investigated in this study. In total 72 cubes were casted in three sets for experimental purposes. 100% of river sand and 100% of manufactured sand were used in two sets of cubes. Ordinary Portland cement was replaced by 25% of fly ash with 100% of manufactured sand in the third set of cubes. Compressive strength was measured after 7, 28 and 56 days. Water absorption test, water permeability test and sorptivity test were used to investigate the durability properties of concrete. This experimental study shows that replacing manufactured sand instead of river sand in concrete improves the strength and durability properties of concrete.
item: Conference-Extended-Abstract
Laboratory study of the effect of long-term aging and temperature on resilient modulus of dense graded asphalt concrete with lime kiln dust
(2019) Dammika, HTR; Sarukkalige, R; Nikraz, H
The flexible pavements are highly vulnerable to surface damage due to an increase in temperature, excessive load, moisture and aging of asphalt mixes. They should have high engineering and structural performance to have a maximum service life. Resilient Modulus (Mr) is the stiffness or a measure of cohesion of asphalt concrete (AC) mixture. It is an important parameter in pavement design and plays a vital role in flexible pavement durability. Stiffness of an AC mixture is varying with temperature and long-term field condition. Previous researches proved that Lime Kiln Dust (LKD) performs well as a mineral filler and moisture damage reducing agent in Dense Graded Asphalt (DGA) mixture. This paper highlights how LKD effects on the stiffness of DGA mixes with the variation of temperature and aging. Mr is measured by using the indirect tensile method under aged and unaged conditions at 20 oC and 40 0C temperatures. The study was done on DGA 10 and DGA14 mixtures with hydrated lime (HL), LKD and no additive (control mix). SHRP long-term oven aging (LTOA) was used for aging specimens to represent 15 years of field aging in a Wet-No-Freeze climate and 7 years in a Dry-Freeze climate. This research found that LKD and HL based mixtures perform almost the same when considering the effect of aging and temperature on Mr. Stiffness of all mixtures decrease when temperature increases and increase with aging. LKD provides more stiffness to DGA mixtures than HL under long term aging condition. LKD based mixtures show minimum stiffness reduction with the temperature increasing. Therefore, it can be concluded that LKD is an excellent mineral filler that can be used as a substitute for HL to enhance the performance of DGA mixture in terms of high temperature and excessive loading.
item: Conference-Abstract
Effectiveness of community involvement in development projects in Sri Lanka
(2019) Palihawadana, MP; Jayasinghe, C
Various agencies have been involved in multitude of programmes on road construction projects in Sri Lanka. Almost all such programs have been implemented in the nature of supply driven system in which the beneficiaries were not involved in any stage of the implementation of road development programs. Subsequently, it was revealed that the users were not satisfied with the roads that have been constructed without their involvement and also found those roads are not sustainable. Having considered above situation, Road Development Authority has decided to change their supply driven approach in the implementation of road development programs and introduced community based, participatory development approach as an alternative approach, especially to deliver user friendly roads through beneficiary involvement. The problem identified is that there had not been conducted adequate researches/studies to understand the effectiveness of applying community based, participatory development approach as an alternative strategy to achieve the anticipated targets, in the road development projects implemented in the country. Objective of this project is to identify the effectiveness of adopting community based, participatory development approach as an alternative strategy to achieve the anticipated targets, in development projects implemented in the country. Several methods have been used to collect data for research including, literature review, administering a structured questionnaire, Focal Group Discussions with selected community leaders in the project area. Accordingly, 18 numbers of roads have been selected from iRoad project and another 18 roads which were constructed without community participation have also been selected for the sample. It was revealed through the analysis of collected data that the project was able to implement with much success with applying participatory development approach to deliver user friendly roads, in particular (97% respondents disclosed that they are satisfied with the project). It is suggested to apply participatory development approach for forthcoming similar projects to ensure the long term sustainability together with beneficiary satisfaction.
item: Conference-Abstract
Analysis properties of rock mechanics in JIIPE area, Gresik, East Java, Indonesia for tunnel construction using deformation methods in Matlab application
(2019) Indriani, RF; Padlilah, M; Yulianita, D; Widya Utama, DEA
JIIPE Gresik’s Industrial Area, East Java, Indonesia is located in Randublatung depression zone, which is rich of sedimentary rock. In this study, we use two samples sedimentary rock (samples K2 and K5) that have been coring before. We have did calculate dimensions (diameter, height, and mass); axial deformations; transversal deformation of samples K2 and K5 used to determine stress’s value when the rock samples have been fractured and calculated modulus elasticity, so that we can analysis strength of the rock samples can use for raw material of tunnel construction. In this study, we use “versa tester” and “dial gauge” to give compression stress for rock samples K2 and K5 and we got the stress value: 0.937131 MPa rock samples K2 had been fractured, and when the stress value: 0.867409 rock samples K5 had been fractured. Also in this study we got value modulus elasticity of rock samples K2 is 10.13370616 MPa and value modulus elasticity of rock samples K5 is 24.30410248 MPa. After we compared with theoritical value from modulus elasticity of rock and soil, we can know the rock samples K2 is soft clay and rock samples K5 is medium clay. The theoritical value from modulus elasticity of soft clay is 4.1-20.4 MPa and medium clay is 20.7-41.4 MPa. In this paper, next we got curve about stress, strain, and modulus elasticity use MATLAB Apllication. As we can know, clay can’t use for raw material of tunnel construction because of the swelling clay process, properties of its elasticity that is easy to had been fractured and their value of modulus elasticity stated if rock samples K2 and K5 relatives had low strength. However, clay can use for additional material for tunnel construction (cement).
item: Conference-Abstract
Near real time EO satellite data for civil engineering applications : a conceptual design of the data receiving facility in Sri Lanka
(2019) Mahindapala, WKM; Vandebona, AP; Viswakula, SA
One of the oldest engineering disciplines, civil engineering, has many branches such as construction, geotechnical, water resources and transportation engineering; that significantly impact the environment. Sri Lanka, being a biodiversity hot-spot, needs to play a vital role in protecting the ecology. To achieve sustainable development, civil engineers are committed to innovate and they have been carrying out research studies to find out suitability of alternative sites, materials and methods to reduce the environmental impacts. Satellite Earth observation is a non-destructive technology that has been spreading in many fields, including civil engineering domain for investigations, planning, monitoring, damage assessment etc. Satellite data has become an essential input to support civil engineering decisions making, but effective decision making depends on the data availability and access and also, immediate access is necessary to detect rapid environmental changes such as landslides and forest fires. However, technical limitations hinder the provision of useful data in real time. The aim of this paper is to develop a conceptual design of the data receiving facility including civil engineering design aspects, to address the limitations in providing near real time satellite data in Sri Lanka.
item: Conference-Abstract
Acoustic profiling and non linear acoustics finite element modeling of Sugathadasa Indoor Stadium
(2019) Wijesiriwardana, R; Perera, HYR
Acoustic performance of an arena is measured and classified by it’s acoustic parameters. The acoustic parameters are used for the designing of the sound systems and improving the arena’s acoustic performance by proper sound proofing. According to international standards DIN EN 18041, sports arena comes under type A5 and can be changed into type A4/A3/A2 education and communication/presentation halls or type A1 musical halls. During our profiling work some of critical acoustic parameters of Sugathadasa indoor stadium were measured and estimated according to the ISO EN 3382 standard. The primary measurement parameters, reverberation time (RT60dB), center time (TS), early energy fraction (D50) and objective clarity (C80) were measured and then are used for identifying and classifying the arena. The arenas also need to satisfy the noise criteria (NC) standards depending on the event that the arenas are used for and also considering the surrounding environment. Generally, the arenas are changed temporarily depending on an event by increasing the acoustic absorption area and various other sound proofing methods. This paper contains acoustic profile, reverberation time, center time, early energy fraction, noise criteria, the sound clarity index measurements of the Sugathadasa indoor arena. Moreover, the acoustic space of the arena was modelled with nonlinear FEA methods taking the Khokhlov-Zabolotskaya-Kuznetsov (KZK) nonlinear wave equation and Timothy Walsh (TW) numerical formulation of the KZK model. Nonlinear acoustic wave equation was used considering the lager acoustic space of the arena and complex structural, geometrical and surface elements of the arena such as steel trusses, columns, beams, diffusers, absorbers, resonators and reflectors. Moreover, to find the best locations for the speaker arrays the acoustic parameters were estimated by exciting the acoustic space with sound sources at selected locations. The locations were selected by using the simulated result of acoustic ray tracing based FE modelling. By using these results best locations for the arena speaker system was determined. In addition to find out the acoustic frequency response of the current sound system, the arena was excited with white noise, pink noise and brown noise audio signals and then the responses were measured by using microphones placed at selected locations
item: Conference-Abstract
Numerical analyses of cold-formed stainless steel lip-channel beams (ICB) with non-circular web openings subjected to shear
(2019) Ishqy, MFM; Wanniarachchi, KS; Keerthan, P; Gunalan, S; Corradi, M
In recent decades, the application of cold-formed stainless steel structural sections in the construction industry has become increasingly prevalent worldwide due to their favourable material characteristics, improved resistance to aggressive environment, notable corrosion and heat resistance, recycling options and aesthetic appeal. However, the shear behaviour and shear capacity of cold-formed stainless steel members with non-circular web openings have not yet been investigated adequately. Hence a numerical study was undertaken to investigate the shear behaviour and strength of cold-formed stainless steel Lipped Channel Beams (LCB) with non-circular web openings. Finite element models simulating simply supported boundary conditions and non-circular web openings were developed with mid-span loading. They were then validated with currently available shear test results and used in a detailed parametric study. In this research, both stocky and slender cross-sections were considered. The ultimate shear capacities from finite element analyses confirmed that currently available design equations are inadequate to determine the shear capacities of stainless steel LCBs with non-circular (i.e. square and rectangular) web openings. Improved design equations were developed for the accurate prediction of the shear capacity of stainless steel LCB sections with non-circular web openings and expected to be referred in the future when revisions of current cold-formed stainless steel design standards such as American standards (SEI/ASCE 8-02) and European standards (EN1993-1-4) are taken place. This paper presents the details of this numerical study of cold-formed stainless steel lipped channel beam with non-circular web openings, and the results.
item: Conference-Abstract
IOT-Enabled monitoring of historic buildings and surroundings : a conceptual design
(2019) Firdhous, MFM
Historic buildings are considered an important asset for countries and societies as they reflect the cultural past as well as become a source of income for both the country as well as the people living in the area. UNESCO has declared that important historic buildings belong to the entire world irrespective of where they are actually located. Thus, governments and other organizations make special efforts to preserve them. One of the important pre-requisites for effective conservation is the proactive monitoring of them. Effective monitoring schemes need to be vigilant around the clock and alert the responsible parties when attention is required. This paper presents a model for using Internet of Things for effective monitoring of historic buildings. A prototype system was developed to test the proposed model that gives acceptable results.
item: Conference-Abstract
Markov chain models for modelling pipeline deterioration
(2019) Chathumal, RAK; Dias, WPS
A Markov Chain is a model of a sequence of event transitions in which the transitions from one event to other events occur with a fixed probability for a fixed time duration. In general both the events and time steps are taken to be discrete variables. These properties of Markov chains have led them to be used for modelling deterioration processes. Pipeline deterioration is an important infrastructure issue, since most cities worldwide face the problems of managing aging infrastructure. A deterioration model is required in order to plan maintenance budgets effectively, rather than engaging in ad-hoc repairs. While periodic inspections would provide a rich data set for constructing the Markov model, often most public utility agencies can only manage a set of ‘snapshot’ data, where the conditions of pipes (of different ages) have been ascertained at a single point in time, since pipeline inspection is difficult to carry out during service. In this work, we obtain a snapshot dataset of pipeline conditions from the literature. We demonstrate that simple time series modelling is not effective for capturing such deterioration. The Markov chain is defined by an upper triangular matrix - of size 4x4 if we assume 4 discrete states of deterioration as done by the previous authors. Although they have used a Monte Carlo method to obtain the elements of the matrix, we demonstrate that a Genetic Algorithm approach will give similar results. We also demonstrate the variation in level of service of two different maintenance strategies (i.e. the maintenance of pipes at various percentages of different states), where only complete replacement is carried out, but at different time intervals.
item: Conference-Abstract
Numerical investigation of split mullions subject to negative wind action
(2019) Sivaprakasam, T; Kesawan, S; Mahendran, M
In modern facade construction, unitized aluminium framed and glazed facades have gained increasing popularity. In these unitized systems, vertical load bearing member is a split mullion (or mullion couple) made of thin-walled male and female mullions of adjacent panels, thus facilitating pre-fabrication and site assembly. The cross-sectional shape of these mullions are complex, and their shear centre generally lies outside the section. During negative wind action (suction), the male and female mullions would rotate to lean on each other at their unrestrained compression flange, by giving lateral supports to each other, due to eccentricity between the load and their shear centre. Conducting full-scale tests to understand such complex behaviour is expensive and time consuming, thus numerical simulations are preferred in such applications. In addition, finite element (FE) models developed in the previous studies were unable to simulate the real behaviour of mullion couples. Therefore, advanced numerical models were developed in order to investigate the structural behaviour and capacity of mullion couples subject to negative wind action. Full and simplified FE models of three different mullion couples, comprising captive and structural glazing mullions, were developed and analysed. In the full model, mullion couple, glass panes and gaskets/silicone sealants were modelled, whereas, only the mullion couple was modelled in the simplified model. In addition, FE analyses were performed on individual mullion sections, and their capacity predictions were compared with the respective mullion couple analysis predictions. The results from FE analyses were then compared with the moment capacities predicted using the current design approach. Based on the comparisons, suitable recommendations are given for the design of mullion couples subject to negative wind action. Overall, this study has improved the knowledge and understanding of the structural behavior and capacity of mullion couples used in facades.
item: Conference-Abstract
Analyzing the durability and the lateral drainage characteristics of open graded friction course pavement
(2019) Dedigamuwa, KV; Nawaz, RZ; Mampearachchi, WK
In Open Graded Friction Course (OGFC) is a thin permeable layer of special type Hot Mix Asphalt (HMA) which contains a combination of uniform size aggregate skeleton with minimum fines, and high asphalt content. OGFC is being used as an effective pavement material in many countries for expressway construction as it has many positive attributes in performing as a pavement material. During the operational stage of many expressways which were made out of dense asphalt, several issues were observed in wet seasons such as skidding, splash, hydroplaning. OGFC is a suitable solution as a pavement surfacing material for such existing drawbacks. Drainage characteristic of a pavement is one of the important parameters which dominantly contributes to the durability of a pavement. However, the inefficient water drainage due to the lack of drain-ability of vertical drainage caused by the clogging of OGFC lead to observe the properties of lateral drainage. Though, many studies had been carried out to address the clogging effect due to dust particles, no permanent rectification on this issue was found. Therefore, to investigate OGFC in a different way, the lateral drainage characteristics are analysed to identify the water movement on the surface of OGFC by comparing the capacities which can be endured by different types of OGFC. This study analyses the lateral drainage characteristics of OGFC pavement to find out the OGFC gradation which shows the optimum values for the combination of permeability and durability characteristics under the laboratory conditions. Further, the computer image analysis with the aid of MATLAB software is used to analyse the lateral drainage characteristics by identifying and calculating the areas of voids of cross sections captured as 2D photographs by a DSLR camera (Nikon- D3300). The proposed method is less time consuming, comparatively inexpensive and can be utilized to enhance OGFC by integrating with the traditional laboratory experiments.
item: Conference-Abstract
Investigation on effect of partially replacing cement by GGBFS (ground granulated blast furnace slag) in concrete
(2019) Kajaharan, T; Tharsigan, T; Baskaran, K
Strength and durability are two key aspects of the construction industry all over the world. Even though durability still holds an important position and it will have a huge impact in the maintenance period of a structure, at present the importance of strength has overtaken durability considerations due to fast pace of construction. This paper focuses on improving the durability aspects of concrete without reducing the strength of concrete to ensure the fast pace construction in an efficient and eco-friendly way. It would be achieved through the partial replacement of GGBFS (Ground Granulated Blast Furnace Slag) to cement. Cement has been partially replaced by GGBFS up to 30% in the research and several tests were done to find strength and durability properties of concrete. For strength, compressive strength test was done in 7 days (early strength) and 28 days and for durability, water absorption test and sorptivity tests were done. By comparing the results with each other replacements (10%, 20%, and 30%) and control mix by considering both strength and durability properties conclusions and recommendations were made. Conclusions of this research show that the 20% GGBS is a good replacement to cement by considering the strength, durability and future expectations of the industry.
item: Conference-Abstract
Laboratory study of lime kiln dust as a moisture damage reducing agent in dense graded asphalt concrete mixture
(2019) Dammika, HTR; Sarukkalige, R; Biswas, W; Nikraz, H
Road authorities are experiencing a considerable degree of moisture associated distresses such as ravelling and stripping, on flexible pavements. Therefore, it is required to modify asphalt concrete (AC) mixtures to have higher moisture damage resistance. Previous studies have shown that hydrated lime (HL) increases the resistance to the adverse effect of water in the AC mixture. But it has limited usage as it is expensive. The first part of this research project confirmed that lime kiln dust (LKD) is a good substitute for HL as an effective mineral filler in AC mixture and 50% LKD of bitumen binder mass gives the optimum performance. This paper addresses the use of LKD as moisture damage reducing agent in Dense Graded Asphalt (DGA). Stripping potential of LKD was investigated to ensure sustained adhesion between bitumen and aggregates in instances where pavement saturation is evident. Tensile strength ratio (TSR) and resilient modulus ratio (MrR) were used to predict the moisture resistance of DGA mixture and studied the long-term aging effect on those parameters. TSR test was conducted according to the modified Lottman test method and MrR test was performed using the indirect tensile method on mixtures with LKD, HL, and control mix. The test specimens were prepared with an air void ratio of 8±1%. Mixtures with LKD and HL have satisfied Austroads and super-pave mix design specifications which is TSR> 80% and MrR>70% for low moisture susceptibility. LKD and HL mixtures have shown more than 100% for both TSR and HL because the presence of these filler materials cause to enhance adhesion and cohesion bonds within the mixture when water exists. LKD behaves almost the same as HL and provides well resistance for moisture associated fatigue cracking and wheel path rutting deteriorations regardless of the aging conditions. Overall, LKD is excellent moisture damage reducing agent.

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