Road Research Institute Research Articles

EFFECTS OF GUM ARABIC ON THE DENSITY OF LATERITIC BRICKS OF VARYING PARTICLE SIZES OF FINE AGGREGATES

Buildings account for over 37% of global carbon emissions, thereby making the environment unsustainable. The research gap identified is lack of establishing the required optimal content of Gum Arabic that have effect on the density of compressed stabilised earth bricks CSEB from lateritic soil of varying particle size distribution. The study aimed at exploring the effect of Gum Arabic as organic stabilizer on the density of compressed stabilised earth bricks CSEB as an eco-friendly construction material for housing delivery needs in Nigeria. The research method used for the study was experimentation and was analysed using bar charts. Results showed that at 28 days particle sizes between 75µm-600µm, have a bulk density of 2203.03 kg/m3 at 20% partial replacement above the minimum bulk density of 1810 kg/m3 specified by the Nigerian Building and Road Research Institute (NBRRI), furthermore, it has a dry density of 1614 kg/m3 to 1733 kg/m3 at 10% partial replacement. This is above NBRRI minimum dry density of 1500 kg/m3. Particle sizes between 1.18mm-4.76mm have a bulk density of 2203.03 kg/m3 at 20% partial replacement above the minimum bulk density of 1810 kg/m3 specified by NBRRI. It has a dry density of 1598 kg/m3 to 1739 kg/m3 at 10% partial replacement, this is above NBRRI minimum dry density of 1500 kg/m3. It was concluded that, an increase in both bulk and dry densities of CSEB, consequently increases its strength & durability, thermal insulation, and low porosity. The study recommends that GA-based CSEBs should be utilised in building production due to its improved engineering properties.

Durability, sustainability and cost analysis of the effect of SNF superplasticizers on locally produced concrete in Ghana

Using conventional methods of concrete production to achieve expected results is challenging, hence the use of chemical admixtures which is also little researched in Ghana. The study conducted a concrete mix design for project construction, following significant challenges encountered in attaining the desired strength of 30MPa at a slump of S3 (100-150mm). To address the challenge, a concrete mix design was produced according to EN 206 standard mix design at the laboratory of the Council for Scientific and Industrial Research (CSIR)-Building and Road Research Institute (BRRI)-Ghana. A chemical admixture consisting of high-range water-lowering sulfonated naphthalene formaldehyde (SNF) was used in the design. Once the laboratory mix design was completed, the concrete mix proportions were adopted for field application. When employing 385kg/m3 of Portland cement, a water-to-cement ratio of 0.49, a water content of roughly 189kg/m3, and an admixture content of 3.28kg/m3, the laboratory mix design yielded a 28-day compressive strength of 37 MPa (5366 psi). After 28 days of curing, both the laboratory (37MPa) and field-prepared (31MPa) concretes met the minimum strength of 30MPa with the laboratory-controlled concrete exhibiting compressive strength results that were approximately 16% greater than those of the field-prepared concretes. The report revealed that the use of SNF resulted in 18% savings in cement thereby reducing carbon emissions and 5% savings in cost, urging a case for the use of chemical admixtures for structural and non-structural concrete components of the project for the sake of durability, sustainability and cost.

EFFECTS OF GUM ARABIC ON THE MOISTURE CONTENT AND WATER ABSORPTION OF LATERITIC BRICKS OF VARYING PARTICLE SIZES OF FINE AGGREGATES

The increasing greenhouse gas emissions associated with construction, accounts for 37% global emissions. In mitigating these challenges, the Nigerian Building and Road Research Institute (NBRRI) recommends the use of lateritic bricks due to it's environmental sustainability. To achieve durability and environmental sustainability, Gum Arabic is introduced in laterite soil to improve its properties. The objective of the study is to determine the suitability of Gum Arabic as stabilizer on the moisture content and water absorption capacity of earth bricks of different particle size distributions. Experimental research method was adopted for the study. The particle size distribution of the laterite soil was classified within the ranges 75µm-600µm, and 1.18mm- 4.76mm. Also, the content of the Gum Arabic was proportioned from the range of 0% to 30% partial replacements. Sample bricks were produced and tested at 14, 21 and 28 days curing period. The data collected from the results of the laboratory experiments was analysed using bar charts. The results showed that, particle size distributions for grading fine aggregate suitable for compressed stabilised earth bricks (CSEB) was found to be between 1.18mm-4.76mm considering it low extent of permeability and high durability properties at 28 days curing period. It was concluded that, moisture content influences the rate of water absorption, such that an increase in moisture content consequently increases the rate of water absorption. However, the low extent of water permeability recorded, reduces the water content in the pores of the CSEBs, thereby reducing the extent of expansion and contraction making the GA-based CSEBS to be less brittle and more durable. It was recommended that, when selecting eco-friendly bricks for construction of buildings, Gum Arabic based Compressed Stabilised Earth Bricks (GA-based CSEBs), should be utilised considering its low permeability and durability for particle size ˃ 600µm.

Predicting Traffic Flow with Neural Networks

The monitoring and analysis of traffic flow has become crucial for transportation planners to best schedule road infrastructure repair projects as well as for people to better plan and manage their daily commutes. Therefore, one of the most crucial needs of traffic management systems is the capacity to precisely predict the type of traffic stream. In this study, we will give an intelligent approach to traffic flow prediction using actual data from the Central Road Research Institute (CRRI), India for the years 2018 and 2019. The suggested method is to train a neural network model to predict traffic flow on an hourly basis in the future. The simulation's conclusions provided a reliable forecast for the traffic statistics

Testing & Evaluation of Road Bounce PRO-Mobile Phone App Based Technology for Road Measurement

Road roughness plays a crucial role in assessing the overall condition of a road. It impacts various factors such as vehicle operating costs, speed, comfort, safety, fuel efficiency, and wear and tear. Every road user seeks a smooth and pleasant driving experience. The measurement of road roughness is a key task that influences maintenance decisions. According to the Indian Road Congress (IRC) standards, roughness measurements should be conducted every 6 months on highways to determine the necessary functional overlay requirements based on the roughness index. Roughness measurements using profile meters namely Rod & Level, Dipstick, Merlin etc. all are time consuming. The Road Roughness Measurement System (RTRRMS) is a system installed on vehicles to assess how the vehicle reacts to the pavement profile. In India, the Central Road Research Institute (CRRI) has developed a 5th Wheel Bump Indicator that is mounted on cars to measure roughness. The RTRRMS 5th Wheel Bump Indicator utilizes binary true/false information and range-based analog data generated by digital accelerometers commonly found in smartphones. This measurement system is facilitated through an application called "ROAD BOUNCE”. This paper aims to showcase the results obtained from the testing and assessment of an App-based roughness measurement technology in terms of its precision and user-friendliness. The evaluation was conducted across various vehicles and mobile phones, considering different factors such as speed, tire pressure, gradients, and more. Keywords:- Road Bounce, RTRRMS, Roughness Measurement, Cell Phone based Roughness.

EXAMINING THE FACTORS CONFRONTING THE EXECUTION OF GETFUND CONSTRUCTION PROJECTS IN THE UPPER WEST REGION, GHANA

GETFund's primary goal is to offer a specialized financial source to increase government budgetary allotments for the construction of educational infrastructure at all educational levels, from pre-tertiary to tertiary, as specified in the GETFund (2000). The aim of this study is to examine the managerial skills and issues that GETFund contractors employ. The aim of this study is to investigate the challenges faced by GETFund construction project managers, pinpoint the factors that affect GETFund project performance, and suggest practical solutions to improve GETFund project execution in the Upper West Region. For this study, a descriptive survey research design was chosen. One hundred and forty-eight construction firms, twenty-one consultancies, and sixty-five clients made up the sample for the study. A questionnaire was the main method used to collect data. A descriptive statistical analysis was performed on the data. The study's conclusions showed that political and financial issues are the main barriers to the effective execution of GETFund building projects. Moreover, scheduling, and financial issues pose the biggest obstacles to the region's successful implementation of GETFund construction projects. Furthermore, the survey found that the majority of contractors' agents carrying out GETFund projects lack the technical expertise, resources, and manpower required, which makes it challenging for them to comprehend and interpret the criteria and drawings that project consultants provide them. According to the report, in-service training should be offered by reputable regulatory organizations like the Building and Road Research Institute (BRRI) to improve employees' capacity to manage firms.

Investigation of the Compressive Strength of Sand-Filled Polyethylene Terephthalate Bottles as a Material for Wall Construction

The disposal of plastic wastes in the environment has negatively impacted the environment as plastics are non-biodegradable and contain chemicals that are harmful to humans, animals, plants, and the environment at large. The increased demand for infrastructure across the globe has also resulted in a rapid depletion of natural resources used for the production of construction materials. The need therefore arises for research to proffer solutions that would lead to the better management of plastic wastes, and provide sustainable construction materials. This study evaluated the compressive strength of sand-filled PET bottles (with varying moisture content, 0-15%) and clay bricks incorporating sand-filled PET bottles for wall construction. Cement was used to stabilize the clay at 0%, 10%, and 15% by weight. The compressive strength of the bricks produced was compared with that of control bricks (without sand-filled PET bottles). The results obtained reveal that the compressive strengths of the PET bricks were less than those of the control bricks. An optimum of 2% moisture content of sand is recommended for filling the PET bottles while 15% stabilization of clay with cement is recommended for the production of sand-filled PET bricks. The sand-filled PET bricks can be used for non-load-bearing wall construction as their compressive strengths fall below the minimum requirements of the Nigeria Building and Road Research Institute and the Standards Organization of Nigeria for load-bearing walls.

Shades of grey—tire characteristics and road surface influence tire and road wear particle (TRWP) abundance and physicochemical properties

There is mounting evidence that tire wear particles can harm natural systems, but worldwide trends in car weight and car usage, mean emissions are set to increase. To control tire wear emissions and help understand fate and transport, detailed characterisation of the particles, and the relationship between road surface properties and emission profiles is needed. This study deployed a suite of experiments utilising the advanced road simulator of the Swedish National Road and Transport Research Institute to compare seasonal tire types from three brands. An extraction method was developed for a coarse (>30 µm) fraction of tire and road wear particles (TRWP), and a comprehensive physicochemical characterisation scheme applied to both TRWP and tire-tread, including microscopy, energy-dispersive X-ray spectroscopy and pyrolysis-GC/MS. Road simulator dusts and hand-picked TRWP showed differences in shape, numbers, and mass between tire types and brands, and between asphalt and cement concrete road surfaces. Contrary to accepted perceptions, tactile analyses revealed that firm-elastic TRWP comprised only a minor proportion of TRWP. Fragile and chemically distinct tire-road-derived particles, termed here sub-elastic TRWP, comprised 39–100% of TRWP. This finding raises urgent questions about overall TRWP classification and identification features, resistance to weathering, and environmental fate. At the same time, differences in TRWP generation between tire formulations, and road surfaces, show potential for controlling emissions to reduce global impacts.

Characteristics determination for milling working equipment of excavator

Introduction. The long network of pipelines on the territory of our country needs timely and high-quality repairs. The entrenching tool used so far increases the complexity of work on the overhaul of pipelines, which forces to create solutions for mechanizing the process of digging the pipeline. The purpose of the study conducted in this article is to determine the performance and total torque of the working equipment of the excavator. A general view of the working equipment with the designation of the positions necessary for the study is given. Methods and materials. The concept of specific values of torque and power per one cutter of working equipment has been introduced. The dependencies of the total productivity of the cutters and the torque of the cutters are established. Due to the peculiarity of the design of the working equipment, each of the dependencies is considered separately for the front and rear incisors. The surfaces that reflect the influence of the angular velocity of rotation of the milling head and the angle of installation of the cutters on the parameters under the study are constructed. Results. Based on the obtained dependence of the total torque of the milling working equipment, a nomogram was compiled. By setting the number of N cutters, the speed of rotation of n working milling head and the number of strokes of the DorNII (Road Research Institute) striker, it is possible to determine the required torque of the hydraulic motor. Сonclusions. According to the results of the theoretical study of the process of cutting soil with the help of excavator milling working equipment, the dependencies of the total productivity and total torque of the working equipment were established. The constructed graphic dependencies help to determine the degree of influence of design and operating parameters on the work process. The created nomogram is recommended for use in the design of working equipment.

Biografia inżyniera Jerzego Budzyńskiego (1892-1979) na podstawie zasobu archiwalnego Instytutu Badawczego Dróg i Mostów

The article describes the life of Jerzy Budzyński, born in 1892 in Warsaw, a student of the gymnasium branch of the Warsaw E. Konopczyński School, a student of the Belgian University of Liège, and a graduate of the Warsaw University of Technology. Fragments of his unpublished diary show how Polish independence organizations were formed in the early 20th century: the Association of Polish Progressive and Independence Youth “Filarecja”, the Union of Active Struggle, the Riflemen’s Association, and the Polish Military Organization. The content of the justifications for the applications for the threetime decoration of the Cross of Valor document Jerzy Budzyński’s participation in the capture of the Mokotów Airport in Warsaw in November 1918 and the self-sacrificing fight in defense of Łomża against the Soviet III Cavalry Corps of Gai-Khan (Gai Dmitrievich Bzhishkyan), at the end of July 1920. During the interwar period, Budzyński was the head of the Road Traffic Division of the Road Department in the Ministry of Transport, creating conditions for the development of road transport and the construction of modern roads in Poland. After the war, as the head of the Poviat Road Administration in Grójec, he rebuilt roads and bridges, e.g. using bridge structures donated by the United Nations Relief and Reconstruction Administration (UNRRA). Budzyński ended his professional career working at the Central Research and Development Center for Road Technology (currently the Road and Bridge Research Institute) as the manager of the Center for the Scientific, Technical and Economic Information and Documentation, disseminating world achievements in road technology in Poland. Jerzy Budzyński’s personal file has been preserved in the archives of the Road and Bridge Research Institute, containing source documents of great value for research on the history of Poland in the 20th century.

Influence of Different Curing Conditions on Some Properties of Nigerian Building and Road Research Institute (NBRRI) Leterite Interlocking Bricks

Influence of Different Curing Conditions on Some Properties of Nigerian Building and Road Research Institute (NBRRI) Leterite Interlocking Bricks

A comprehensive study of child pedestrian crash outcomes in Ghana

A comprehensive study of child pedestrian crash outcomes in Ghana

Common-Mode Clutter Filtering for the Problem of Sounding Multilayer Media Using Ground-Penetrating Radar

Eliminating common-mode clutter in data is one of the key aspects of road sensing with GPR. Common-mode interference can occur as a result of multipath propagation of an electromagnetic signal when the reflected signal from the same object arrives at the receiver from different directions and with different delays. Similar phenomena also occur when using antennas raised above the surface due to multiple reflections between the air–surface interface and the antenna. These interferences can significantly distort the data received by the GPR and interfere with the accurate determination of the parameters of the roadway. Therefore, the elimination of common-mode clutter is an important task to improve the quality of the obtained results. In this paper, we consider a method for filtering common-mode clutter in the radar data of the multichannel GPR “Terrazond”, which were obtained by sounding a test section of a highway. The results obtained during filtering can then be used to determine the thickness of the pavement layers using approaches that take into account the signal delay determined by the amplitude jump, for example, the common point method or if the permittivity of each layer is known. The obtained thicknesses of pavement layers are compared with the results obtained during core drilling by the Russian Road Research Institute.

Socio-Economic Factors Contributing to Crashes Involving Motor Tricycles in Greater Kumasi Metropolitan Area, Ghana

Commercial passenger motor tricycles are a recent addition to the vehicle mix in urban areas of Ghana having been introduced in about 2015. While they serve a good purpose and fill a niche in the transport market in Ghanaian cities, this mode of transport is characterized by several road crashes that sometimes result in fatalities. Consequently, the objective of this study was to understand social and economic factors as well as motor tricycles’ operational characteristics and related crashes. A detailed study of this mode of transport in the study area revealed that the socio-economic factors that contribute to crashes involving commercial motor tricycles include the revenue per day, amount spent on fuel per day, and operating days, but with a negative relationship between daily revenue and amount spent on fuel and crash severity. Operational characteristics studied revealed a general improvement in operators’ level of education, a situation where owner-operators are more careful with their vehicles, patrons’ preference for new tricycles, and relatively good returns from operations of these vehicles. Operators also work for long hours and on all days of the week. Further analysis of the data revealed that there are major safety concerns. While the Building and Road Research Institute (BRRI) reports a fatality share of 28% with an annual increase of 3.9% for motorcycle-related crashes in Ghana, the National Road Safety Authority, in the year 2010, indicated a crash rate of more than 50% which is yet to be updated. Recent data for 2019 published by the BRRI estimate a rate of 8.15 fatalities per 10,000 vehicles with a total of 829 total crashes in 2019 for motorcycles, tricycles, and rickshaws and 2.7 motorcycle fatalities per 10,000 vehicles. Similar data are yet to be estimated for motorcycles and commercial tricycles in the Greater Kumasi Metropolitan Area. However, our study revealed a crash rate of 67% for motor tricycle operators in the study area on account of an increase in population, low initial capital cost, and the ability to maneuver in inaccessible areas. It is recommended that, in view of the preponderance of passenger tricycles in the study area, massive educational campaigns involving all stakeholders be pursued.

Towards Promotion of Road Safety: Crash Diagnosis for the Odumasi-Oterkpolu Road, Ghana

Crashes in road curves contribute significantly to road traffic fatalities in developing countries. The crash risks increase when there are multiple vertical and horizontal curves on the road section. In this study, we diagnose the crash-contributing factors along the crash-prone and curvy Odumasi-Oterkpolu road in Ghana and propose countermeasures. Spot speed counts were done using radar guns in addition to manual traffic counts, field inspections, and victim self-reports. Secondary police crash data (from 2015 to 2019) were collected from the Building and Road Research Institute of Ghana. Multiple regression and descriptive analyses were computed to identify crash-contributing factors. Vehicle brake failure and driver inattention were identified as the main driving errors that contribute to crashes in the road curves. Notably, the majority of crashes involved movements in left-turning lanes, in other words towards drivers’ left sides. Speed, traffic volume, and the volume of motorcycles and medium trucks had the strongest association with fatalities. Overall, the road lacks street lights, guardrails, road signs, road markings, posted speed limits, and durable pavement. This is the first empirical investigation of the studied road; therefore, the findings and proposed countermeasures will help to improve road design and safety measures.

Biochemical Parameters and Air Pollution Tolerance Index of Trees along New Ife Road and Within Forestry Research Institute of Nigeria in Ibadan, Oyo State, Nigeria

Poor air quality is one of the renowned issues instigating health complications in urban areas today due to man’s exposure to various gases. The paper assessed the ambient air along New Ife Road (NIR) and Forestry Research Institute of Nigeria Headquarters (FRIN), Ibadan, Oyo State using Biochemical changes and computed the air pollution tolerance indices from fresh leaf samples of ten (10) similar plant species selected randomly in triplicates in both study locations. Monoon longifolium, Chrysophyllum albidum, Terminalia catappa, Dacryodes edulis and Terminalia ivorensis had tolerant APTI values; Mangifera indica, Psidium guajava, Terminalia ivorensis, Terminalia catappa and Cocos nucifera were intermediate APTI while Mangifera indica, Moringa oleifera and Azadirachta indica were found to be sensitive to air pollution. The APTI values at both locations are not significantly different; therefore NIR and FRIN are rated as areas of high anthropogenic activities. Terminalia ivorensis, (31.58 in NIR) Terminalia catappa (30.56 in FRIN) Dacryodes edulis, (31.15 in NIR and 34.76 in FRIN) (Chrysophyllum albidum (34.78 in NIR and 39.78 in FRIN) and Monoon longifolium (49.83 in NIR and 57.50 in FRIN) were classified as sink of air pollution based on their APTI values which ranged from 30>100 obtained in both locations of study. It is however suggested that these plants identified as sink of air pollutants, should be used for landscaping and planted 50m from the roadside for bio-filtration of the atmosphere.

Risks of Implementing Sustainable Construction Practices in the Nigerian Building Industry

This study assessed the risks level associated with implementation of sustainable construction practices through a questionnaire survey distributed to 256 building professionals in Nigeria. It identified 47 risk factors with different likelihood of occurrence and magnitude of impacts. A quantitative risk analysis result based on mean value method and risk prioritisation number showed that the three top-ranked risk factors with highest likelihood of occurrence were unavailability of sustainable materials and equipment, more complex and unfamiliar construction techniques and processes, and high initial sustainable construction costs; whereas the three top-ranked risk factors with highest magnitude of impacts were high initial sustainable construction costs, poor and inefficient communication among project participants, and high cost of sustainable materials and equipment. The criticality index result identified 23 critical risk factors which mostly related to knowledge and awareness, cost, regulatory framework, building materials and socioeconomic issues. However, the Wilcoxon Signed-rank test result indicated that there is significant difference (z = -3.207, p<0.001) between the likelihood of occurrence and magnitude of impacts of the risks factors associated with implementation of sustainable construction practices in Nigeria of which the effect was moderate (r = 0.468). Furthermore, the study revealed that there is no significance difference in the risk level of the risk factors associated with implementation of sustainable construction practices based on the respondents’ roles (p>0.05). The study, therefore, recommended for training of construction practitioners in the multi-risk management approaches and increasing awareness through education on sustainable construction concept for building industry stakeholders. It further recommended for developing of new sustainable and affordable building materials through research institutes like Nigerian Building and Road Research Institute (NBRRI) with appropriate regulatory and policy frameworks for successful sustainable building projects.

Assessing The Challenges of Executing State Sponsored Projects in Ghana: A Case of Getfund Construction Projects in The Upper West Region

The core mandate of GETFund is to provide funding to supplement government budgetary allocations in the provision of educational infrastructure at all levels of education from pre-tertiary to tertiary level as stipulated in the (GETFund Act, 2000 Act 581). The study aims to evaluate the challenges and managerial skills adopted by GETFund contractors. The study's objective is to examine the challenges of GETFund construction projects, identify factors affecting GETFund projects and devise effective strategies to enhance effective GETFund project execution in the Region. The study adopted a descriptive survey design. Sixty-five clients, twenty-one consultants, and sixty-two contractors totaling one hundred and forty-eight were sampled for the study. Questionnaires, interviews, and observation were the main methods adopted for data collection. The data were analyzed using descriptive statistics. The study revealed that the most leading challenges affecting the efficient execution of GETFund construction projects are political and financial. Furthermore, the most leading factors confronting efficient GETFund construction projects execution in the Region are cost and time. In addition, the study revealed that most of the contractors' agents executing GETFund projects do not have the requisite technical personnel, expertise, and resources, making it difficult to understand/interpret drawings and other specifications given to them by project consultants. The study recommended that professional regulatory bodies such as Building and Road Research Institute (BRRI) organize in-service training to improve the management skills of companies.

Viastructura – A New Way Of Pavement Structure Design

The catalogues of standard pavement structures are common way to design road pavements. In 2019, new regulation for the design of standard pavement structures KPT SDK 19 was issued in Lithuania. One of the new requirements require verification of layer thickness of high-class pavement structures. Such verification should be done by internationally approved mechanistic-empirical methods. In addition, it is recommended to use the same methods to adjust the layer thickness of the selected standard pavement structure for lower classes. These calculations are particularly applicable when the design load (ESAL) is at the lower or upper limit of the class range. Vilnius Tech Road Research Institute experts and outsource IT specialists spent two years for the design model ViaStructura development. Web software based on mechanistic-empiric approach include the boundary conditions, based on Austria, the United States and Germany experience and laboratory test results of construction materials. Materials can be selected from created database, which can be simply expanded with the new materials by the user. as Additional function allow comparison of separate designed pavement structures. The article present the concept of the ViaStructura model for the design of flexible pavement structures, reveals its main principles and advantages comparing to the pavement structure selection by the standard catalogue.

Influence of Calcined Clay on the Strength Characteristics and Microstructure of Recycled Aggregate Concrete for Sustainable Construction

Utilization of concrete wastes as aggregate in conventional concrete is regarded as a promising way of achieving sustainability within the built-up environment. This study investigated the performance of high strength concrete produced using recycled aggregate (RCA) with the addition of calcined clay in the concrete mixes. The recycled aggregate was sourced from concrete rubbles and treated by soaking in water, while calcined clay was sourced from the pilot pozzolana plant of the Nigerian Building and Road Research Institute (NBRRI). The recycled concrete aggregates were used as a replacement for coarse aggregate at levels of 0, 20, 40, 60, 80 and 100%, using a mix ratio of 1:1:2 at a constant water-binder ratio of 0.25. Superplasticizer was added to ensure the workability of the mixes. The calcined clay was added at 15 and 20% partial replacement for cement in the mixes. Physical and chemical properties of the materials used were determined, while the workability of the concrete mixes was examined using the slump. The compressive strength of the hardened concrete was determined after 7, 28 and 56 days of curing using 100 mm cube samples. Scanning Electron Microscope (SEM) was used to evaluate the morphology of selected concrete. Results showed that soaking of the recycled aggregate in water limit the water absorption rate of the RCA aggregates in the mixes, while the addition of calcined clay was observed to slightly reduce the workability of the concrete mixes. A reduction trend in compressive strength was noticed as the percentage of recycled aggregate increases, however, a significant increase in compressive strength was observed with the addition of calcined clay at 15% cement replacement. An optimum concrete mix containing 20% recycled aggregate and 15% calcined clay showed improve performance compare to the other mixes. The implication of these results suggests that recycled concrete aggregate can be used for the production of sustainable structural concrete.