bluuebunny/crossref_metadata_2025 huggingface dataset:
Aerobic treatment of POME with indigeneous individual and consortium bacteria
Authors: Said Muhammad , Rayahu Rizki Muthiah , Yuliani Annisa Dela , Faizal Muhammad
Published: November 2019

Palm Oil Mill Effluent contains high value of COD, BOD and TSS being able to pollute the water body. Application of aerobic indigeneous bacteria for treatment of the POME was conducted to reduce the value of COD, BOD and TSS. Bacillus cereus ATCC 14579 (KP 1.1), Pseudomonas azotoformans strain NBRC 12693 (KP 1.3) and Burkholderia cepacia ATCC 25416 (KP 2.2) were used to degrade the components of cellulose, protein and lipase in the POME, respectively. The consortium of bacteria were also applied for degradation of POME. The research was conducted in four bioreactors of 12 litres with variation of time 3, 6, 9, 12, 15, 18, 21 and 24 hours. Parameters observed in the research consisted of bacterial population, COD, BOD, TSS and pH. The experimental results showed that the highest population of bacteria of Bacillus cereus ATCC 14579 (KP 1.1), Pseudomonas azotoformans strain NBRC 12693 (KP 1.3), Burkholderia cepacia ATCC 25416 (KP 2.2) and the bacterial consortium were 8.4 × 107 CFU/ml, 8.5 × 107 CFU/ml, 8.2 × 107 CFU/ml and 9.4 × 107 CFU/ml, respectively. The lowest COD value obtained for those bacteria were 22.6 mg/l, 12.3 mg/l, 14.4 mg/l and 11.8 mg/l, respectively. The lowest BOD values were 9.2 mg/l, 4.4 mg/l, 5.2 mg/l, dan 2.9 mg/l while those of TSS value were 3.2 mg/l, 3.0 mg/l, 4.0 mg/l and 4.2 mg/l. Values of pH ranged from 6.7 to 7.6 for Bacillus cereus ATCC 14579 (KP 1.1), from 6.8 to 7.4 for Pseudomonas azotoformans strain NBRC 12693 (KP 1.3), from 6.9 to 7.5 for Burkholderia cepacia ATCC 25416 (KP 2.2) and from 6.7 to 7.5 for the bacterial consortium.
Mechanical properties of polypropylene plastic waste usage and high-density polyethylene in concrete
Authors: Jonbi Jonbi , Meutia Wita , Tjahjani Antonia Rosalia Indra , Firdaus Angga , Romdon Sahri
Published: November 2019

Using plastic waste as a construction material was one of the techniques used to overcome the inconsistencies associated with environmental pollution created by indiscriminate dumping of plastic waste. It was refined into aggregates that were utilized as a fractional replacement for coarse aggregates in concrete mixtures. The sole objective of this research work is to analyze the use of plastic waste in concrete. Two types of aggregates extracted from plastic waste namely: Polypropylene (PP) and High-Density Polyethylene (HDPE) were used in carrying out this study. The percentages of PP used were 5%, 10%, 15%, while 15%, 20%, 25% were used for HDPE. Similarly, the slump value, compressive strength, and tensile strength were tested for 28 days and at a concrete age of 3.7. The results obtained proved that a percentage increase in plastic aggregate would invariably reduce the value of slump, compressive strength, and tensile strength. The optimum percentage of PP and HDPE used were 10% and 15% respectively. This research contributed to providing an alternative to overcoming plastic waste.
Safety Factors in Public Buildings against Earthquake Risk in the City of Padang, Indonesia
Authors: Yulcherlina  , Abd Majid Muhd Zaimi , Zin Mohd Rosli M , Edrizal
Published: November 2019

Earthquake resistant structures for public buildings should be designed and built whereby they are supposed to withstand earthquake with minimum damage and without catastrophe collapse. As no structure can be entirely immune to damage due to earthquake, the goal of earthquake resilient building is to ensure that the risk of collapse can be minimized or reduced. Therefore, there is a need to identify all factors that could contribute to the risk of failures due to earthquake especially on public buildings. Based on code of practice, earthquake building resistant structures are intended to withstand the largest possible earthquake which is likely to occur in a particular area where in this paper discussed the study of earthquake in Padang, Indonesia. This paper presents on safety factors that need to be considered in the analysis and design of public building for the city of Padang, Indonesia due to earthquake. Recently, there are several design approaches in earthquake engineering studies such as experimental results, computer simulations and observations from past earthquakes to understand the performance of the damaged building. However, the data from past earthquake that occurred in Padang, Indonesia is to be analyzed so that the safety factors on the risk of the public building can be well understood. Factors such as height of building, type of structures, material of construction, types of soil, and method of construction are considered in this study. The research findings on the city of Padang, Indonesia have concluded that all new buildings should be designed base on earthquake code of practice where the use of base isolator and stiff construction are to be introduced for public building structures.
Image-based non-destructive evaluation method for building condition assessment
Authors: Ng Hui Lin , Jaw Siow Wei , Hashim Mazlan , Shek Poi Ngian , Lim Kar Seong
Published: November 2019

Building condition assessment (BCA) is one of the important approaches in total asset management during the asset life cycle. BCA is to monitor the functional status of the asset during the asset use and maintenance phase in the asset life cycle. With regards to this, various non-destructive evaluation (NDE) technologies are adopted for building structure physical condition assessment from time to time to prevent any catastrophic incident to occur. Two case studies on inspection of internal structure condition of concrete wall and slab using image-based NDE were presented in this study. A well-known NDE technology, namely ground penetrating radar (GPR) was used to scan the concrete wall and slab to identify the internal structure condition of the concrete wall and slab. The GPR radargram obtained by the shorter wavelength radar signal is evaluated to resolve the internal structure and the defect in detail. Results of this study prove that GPR can detect the internal structure of the concrete wall and locate the moisture in the concrete slab due to poor waterproof design. With such convincing results, the application of GPR has set a new benchmark in BCA for building physical condition assessment; a crucial aspect for better building maintenance and management in total asset management.
Effects of bleeding on corrosion of horizontal steel bars in reinforced concrete column specimen
Authors: Sandra Nevy , Kawaai Keiyu , Ujike Isao , Nakai Ippei , Nsama Willick
Published: November 2019

The durability of reinforced concrete proved to be predominantly controlled by the resistance against ingress of harmful substances including chloride ions, carbon dioxide, and moisture. The corrosion of steel bars taking place especially in a marine environment was likely to be severe, which depends on the availability of oxygen and moisture consumed by cathodic reactions. This study aims to investigate the effects of bleeding on the corrosion of horizontal steel bars placed in reinforced concrete column specimens. This was examined through electro-chemical tests including the half-cell potential, polarization resistance, and corrosion current density carried out using specimens in which corrosion was induced via dry and wet (NaCl 10%) cycles. The presence or absence of copper slag fine aggregate and fly ash replacement were taken up as experimental factors. The results suggested that the corrosion of horizontal steel bars in the upper part of the column concrete specimen was adversely affected even for the case of OPC specimens with relatively lower bleeding water. This was attributed to less resistance against the ingress of corrosive substances especially in those locations. In the case of fly ash mixtures, the corrosion resistance was significantly improved owing to lower oxygen permeability measured via cathodic polarization technique.
Components of Cost Overrun in China Construction Projects
Authors: Mansur Shaiful Amri , Zin Rosli Mohamad , Linbo Liu
Published: November 2019

This paper concerns an investigation into the causes of cost overrun in the construction industry of China. Cost overrun is common in all the countries of the world. For example, China has been experiencing severe cost overrun problem in the construction industry. The aim of the paper is to evaluate the major factors giving impact on cost components including labour, material, equipment and subcontractor. General factors that caused cost overrun in construction projects were obtained from literature review. The first questionnaire was designed to identify severity of factors for each cost component. The second questionnaire was designed to obtain the average proportions of cost components and cost of each top-ten factors for each cost component. The survey findings indicated that low productivity of labour, escalation of material prices, high cost of machineries and cash flow, and poor financial management are possible causes related to cost overrun in construction project of China as compared to other factors.
Assessment of Bridges for Tsunami Evacuation Route Plan in Padang: Survey of Existing Condition and Identification of Problems
Authors: Rita Eva , Permata Robby
Published: November 2019

Padang, as one of the tsunami prone city in the world, had already prepared itself for the upcoming event. Local government already issued tsunami evacuation plan, and assigned several buildings as temporary evacuation facilities or shelters. One important thing in this mitigation plan is the performance of the infrastructures as roads and bridges. Bridges are essential since any damages or failures leads to disruption or even widespread jam of traffic after the big earthquake. Draft of new seismic code for bridges in Indonesia suggests that bridges for evacuation plan must be designed with very limited damage or near elastic design. This study attempts to identify bridges that are included in tsunami evacuation plan route and summarizes the existing condition. The collected data and information are important and could be used as basic for future studies such as retrofit plan.
Wind Tunnel Testing for Vibration Analysis of High Rise Building Due to Wind load
Authors: Andika Matza Gusto , Fariduzzaman
Published: November 2019

Wind load can induce vibration on high rise building which can cause discomfort to occupants and fatigue in structural members and connections caused by fluctuating wind loads. Vibration on high rise building due to wind load can cause by vortex shedding around the building. Wind tunnel testing is a way to asses vibration on high rise building because of wind load. With doing wind tunnel testing we can analyze vibration cause by vortex shedding which call vortex induced vibration. In this research vortex induced vibration occur at wind speed 8.4 m/s in wind tunnel which excited high rise building dynamic model with 4.1 Hz first natural frequency. The other phenomenon which can be analyze in this research is lock-in phenomenon, lock-in phenomenon is start at 7.8 m/s wind tunnel speed which induce model natural frequency structure at 4.1 Hz, when the wind speed is up to 8.4 m/s the frequency still at 4.1 Hz but the vibration amplitude is rising, and when the wind speed is up to 8.9 m/s the vibration amplitude is decline at the same frequency at 4.1 Hz, when the speed is more than 8.9 m/s the frequency is more than 4.1 Hz and the amplitude decline until the next model natural frequency excited by vortex shedding frequency.
Sentiment analysis and relationship between social media and stock market: pantip.com and SET
Authors: Padhanarath P , Aunhathaweesup Y , Kiattisin S
Published: November 2019

This research constructs a process flow of social media sentiment analysis and explains relationship between comments on social media and stock. One of the popular social media for Stock Exchange of Thailand investors is Pantip.com, a website providing service as a webboard with tagging feature. In this research, all posts tagged by ‘Stock’ on this website were crawled to files. Then comments were scraped and cleaned. For model training, some comments were labelled into three classes; positive, negative and neutral. Sentiment analysis model was constructed by Naive Bayes Classification technique. In evaluation, the model shown that it performed 74% accuracy. This model was utilised to classify comments into sentiments. When all comments were completely classed, sentiment types were counted by date. Finally, correlation matrices were constructed to find relationship between number of sentiments and stock. The research found that number of sentiments from social media relate to ADVANC and CPALL stock volumes. Moreover, the correlation always reaches to the peak on trading day then it gradually declines with the magnitude depending on the day length after trading day.
Kerosene Like Fuel Characteristics from Municipal Solid Plastics Waste Pyrolytic Oil for Domestic Purposes
Authors: Suhartono
Published: November 2019

The aims of the research are to characterized pyrolytic oil as fuel and utilize it for heating purpose. The pyrolytic oil was characterized to decide whether this oil can be used as fuel for the desired application or not. The highest pyrolytic fuel yield of about 67.48% w/w was obtained from converting of 3000 g of plastic waste at pyrolysis time, topt. of 240 minutes and a pyrolysis temperature of 360 °C in a small pilot-scale batch reactor. The characteristic of pyrolytic fuel had an average value of density and viscosity were 771 kg/m3, 1.031 cSt, respectively. The combustion quality as other characteristics of the fuel was obtained as heating value, flash point and auto-ignition point of 37.996 MJ/kg, 48 °C and 240 °C, respectively. The similar functional groups of pyrolytic oil and commercial kerosene fuel were found in Fourier-transform infrared spectroscopy (FTIR) spectrum. This pyrolytic oil provided a higher flame temperature of 1300 °C and a higher thermal efficiency of 33% upon utilized as fuel using a modified pressurized cook stove. These pyrolytic oil’s parameters are close to the standard values of the kerosene fuel.
Air Temperature and Humidity Outdoor Analysis of Buildings in Panakukang Makassar
Authors: Mustamin Tayeb , Rahim Ramli , Baharuddin  , Mulyadi Rosady
Published: November 2019

This study aims to analyse data and humidity outside. Data retrieval is taken from the HOBO MX2300 tool data recorder for external temperature and humidity. Then the data processing was analysed and analysed using a Microsoft Excel program in the form of graphs / fluctuating images that showed the average value, standard deviation, maximum value, and minimum value. Only from 6:00 to 8:30. On the 15th to the 17th of June the thermal comfort zone only occurs in the morning under 09.00. The highest maximum air temperature occurs on June 15 at 13.01-13.30. The lowest minimum value is on June 15 at 06.00-06.30. The results of the analysis then show the level of suitability of the data with the thermal comfort zone based on SNI (SNI) every day.
Characterization of porous hydroxyapatite-alumina composite scaffold produced via powder compaction method
Authors: Gunawan Gunawan , Arifin Amir , Yani Irsyadi , Indrajaya Muhammad
Published: November 2019

Recently research on hydroxyapatite bioceramic material has been carried out rapidly to support the needs in the medical field. The study aims to develop porous bioceramic from hydroxyapatite Al2O3 composites. Porous hydroxyapatite Al2O3 composites were prepared with variation of the weight fraction of Al2O3 reinforcement and green bean starch space holder used as porous maker. The manufacturing process begins by mixing hydroxyapatite powder (200 μm), Al2O3 powder (55 μm) and green bean powder (200 μm) using a Ballmill with a rotating speed of 225 rpm for 1 hour. The mixture is then put into a mold and compressed in a unidirectional compression device at a pressure of 2000 psi. Green body specimens are then sintered at a temperature of 1200°C and holding time for 3 hours. The apparent density test was carried out using the Archimedes’ method and the highest density was 1.95 g / cm3 with 41.915% porosity in the specimen with 25% Al2O3 weight fraction. The results of the compressive test showed that specimens with a weight fraction of 25% Al2O3 had the highest compressive strength of 1.01 MPa with a porosity of 41.915%. The morphology observation using the Scanning Electron Microscopy (SEM) showed interconnecting porous had been formed.
Fatigue Endurance of Aluminium Casting 7xxx Series as Alternative Material for Organic Rankine Cycle’s Turbine Blade at 180 °C Operation Temperature
Authors: Eka Utami Nurhabibah Paramitha , Ellyanie  , Astuti
Published: November 2019

Organic rankine cycle (ORC) Turbines are very promising for converting heat in low temperatures from 100 to 220 ° C into electrical energy. The use of Fe-25Al-xTi and TiAl alloys as ORC turbine blades encourages the need for development in utilizing lighter but stronger alternative materials. This study analyzed and observed the fatigue resistance of Al-Zn-Mg-Cu alloys as an alternative material by performing chemical composition analysis, hardness test, microstructure test, tensile test, fatigue test, and fractography observation. The results show that there is reduction in mechanical properties and fatigue resistance in artificial aged specimens. This is due to the deployment of precipitate which is a decomposed phase causing a decrease in mechanical properties and fatigue resistance in heat treated specimens.
Modernization of facility layout design in earthenware craft industry with green productivity approach
Authors: Oktarini Devie , Suryani F. , Madagaskar  , Rosyidah M.
Published: November 2019

Entering the Industrial Revolution 4.0 as of now there are still many earthenware craft industries that are traditional, both in terms of equipment and materials, procedures for making, and layout of facilities. Layout facility is one of many factors to determining factors of level of productivity workers. If arranged more modern, then the work operation becomes more effective and efficient so that the productivity of the industry will increase. The purpose of this research is redesign the layout of the earthenware craft industry facilities which are modern and having good work environment, improve the work quality of the workers, and increase the profitability of the earthenware craft industry itself. The stage of this research starts from determining the alternative layout of the best facilities, analyzing the layout of the facility using the 5S Method, and analyzing the productivity of the facility layout with the concept of Green Productivity. The results achieved from this research are the best facility layout found in alternative 1, where percentage reduction in path length reached 40% of initial layout. 5S analysis results have a positive impact for time of production process earthenware by reduction in processing time is 42,75% and the electricity savings reduce electricity costs 55,02%. Rate of productivity in this earthenware craft industry has increased by 2.31%.
Revisiting Causative Factors of Project Cost Overrun in Building Construction Projects in Nigeria
Authors: Akinradewo O , Aigbavboa C , Akinradewo O
Published: November 2019

The growing need for construction of all types coupled with a tight monetary supply has provided the construction industry with a big challenge to cut cost. The total cost of construction in normal circumstances is expected to be the sum of materials, labour, site overheads, eEquipment/plant, head office cost and profit but in many parts of the world particularly in Nigeria, there are other costs to be allowed for. To the end user, the added costs are passed on as higher rental/lease costs or prices. The aim of this study is to appraise the causative factors of cost overrun on building construction project in the Nigerian construction industry. This study was carried out using quantitative research method. This involved the collection of data relating to the research study through questionnaires prepared using literature search and carried out among professionals in the construction industry such as Architects, Builders, Engineers, Project Managers and Quantity Surveyors. Random sampling technique was employed in selecting the 156 respondents for the research study within the South Western region of Nigeria. Data retrieved were analysed using Percentile, Mean item Score and Kruskal-Wallis H-test. Findings revealed that additional cost (e.g. variations), poor financial control on site, contract management, previous experience of contractor, wrong estimation method are the major factors leading to cost overrun on building construction projects. The study concluded that construction projects experience cost overrun as a result of negligence in one way or the other by all the stakeholders involved in the construction process from inception to final completion.
Whither the courtyards? Understanding disappearance and transformation of courtyards in residential buildings in Akure, Nigeria
Authors: Adegun O B , Adedeji J M , Adedeji Y M D
Published: November 2019

Courtyards are historically a notable part of residential buildings in South-west Nigeria and other parts of tropical Africa. They perform a range of functions – from the climatic to the socio-cultural. Presently, new residential buildings are excluding courtyards while existing courtyards within residential buildings are being altered. This paper presents a study that investigates the reasons for these in the context of Akure, a medium-sized city in South-west, Nigeria. We conducted twelve semi-structured interviews with three groups of purposively selected participants. These are: those who own and live in houses with courtyards (whether transformed or not), those living in houses without courtyards and built environment professionals (architects and planners). Factors influencing the disappearance/transformation of courtyards include increasing demand for compact and cheaper buildings, changing household lifestyle, climatic/ecological problems, insecurity. This paper proposes means through which the value of courtyards in residential buildings might not be completely lost.
Mapping out research focus for emotional intelligence in human resource management in the construction industry
Authors: Ngwenya L , Aigbavboa C , Thwala W
Published: November 2019

Emotional intelligence (EI) plays a significant role in the delivery of better performance by individuals and organisations. Evidence of its influence can be seen in different human resource management (HRM) activities. However, despite this significant relationship between EI and HRM practices, less emphasis has been placed on this within the construction industry. The few available studies on EI within the industry has placed focused on general issues. This study, therefore, through a review of previous studies mapped out the key area of focus in terms of EI on organisations HRM. Published journal articles and conference proceedings were sourced from ISI Web of Science database. The search of literature was done using keywords such as “Emotional intelligence” AND “human resource management”, with no restriction placed on the publication year or domain of the research. Only articles published in English language were extracted. A total of 70 articles were extracted and analysis were done based on the year of publication, country, and co-occurrence of keywords. The findings of the study revealed that 2017 experienced that highest amount of publications in this area, most of which emanated from the United States. The findings revealed the key area of focus in terms of EI on organisations HRM. Based on the findings, conclusions were drawn, and recommendations made thereof.
Roles and effects of utilizing recent technologies on material management for construction work in South Africa
Authors: Oke A E , Odubiyi T B , Aigbavboa C O , Thwala W D , Nelwamondo Z T
Published: November 2019

The role of technology in every facet of the economy cannot be handled with levity. The construction industry like other germane sectors of the economy thrives best with the adoption of technology in various parts of its subsets. It has been established that Material management can be handled effectively with the use of modern technologies. It is based on this that this research focuses on identifying the roles and effects of adopting modern technological tools for effective material management in the South African construction industry. The study adopted a quantitative approach where questionnaires were administered to professionals in the South African construction industry. Descriptive statistics tools were used to analyse the gathered data. Findings showed that the prevalent roles of adopting technological tools for effective material management in South African construction industry are majorly continuously Progress monitoring; Monitoring mechanisms with regard to stated outcomes are clearly explained from the beginning, and scope and use of materials are explained to all role players. On the other hand, the effects of technological tools are seen mainly as profit maximization; constant monitoring of materials on site and, Aids in planning and clarification of materials before projects begin. The implication of the roles and effects is that there is an opportunity of great productivity in construction industry with the use of technology as it makes things easier while improving principles of management.
Use of natural resins in repairing damaged timber beams – An experimental investigation
Authors: Osofero A I , Corradi M , Benedetti G , Ede A N
Published: November 2019

Different techniques including the application of steel elements, composite materials and polymeric resins have been used in the past to repair damaged timber beams. However, there is a growing need to replace these materials with those with minimal environmental impact. In addition, stringent requirements of conservation authorities on the compatibility between repair and parent materials have also necessitated search for innovative repair materials for timber beams. Therefore, an increasing shift of focus towards the use of materials derived from natural sources in repairing and reinforcing timber structures is currently experienced. This paper presents the results of an exploratory study on the use of natural resins (rosin and bone glue) in repairing oak timber beams. 15 oak timber beams with cross section dimensions of 67 x 67 mm and 1100 mm in length were tested in four-point bending to failure. Undamaged, damaged (unrepaired) and damaged but repaired timber beams (with rosin and bone glue) were tested. The effectiveness of the repair material and technique was analysed based on the bending capacity and mid span deflection at failure. The initial results show negligible effectiveness of rosin in repairing timber beams. In fact, about 16% reduction (average) in load carrying capacity with a corresponding 5% decrease (average) in maximum displacement was recorded. Relatively higher level of effectiveness was recorded with the use of bone glue (about 10 % average increase in load carrying capacity). However, over 30% corresponding average increase in the maximum displacement was also recorded. Further work investigating different repair techniques and other natural resins is presently underway.
The effect of partial replacement of Nigerian Portland limestone cement with rice husk ash agricultural waste in concrete
Authors: Igba U T , Ehikhuenmen S O , Akinyele J O , Osaghale M O , Oyebisi S O
Published: November 2019

Rice Husk is an agricultural waste which when burnt under controlled temperature, produces an ash Rice Husk Ash (RHA) owing to its rich content in silica, which is used as a super-pozzolanic material for the partial replacement of Cement in concrete. Presently, large amounts of RHA are generated in both Rural and Small-Scale Industries which has a high impact on the environment. In this work, Portland limestone cement (PLC) was partially replaced at 0%, 5%, 10%, 15%, 20%, 25% and 30% with RHA. A control of 0% PLC replacement was adopted. Compressive strength was investigated A mix ratio of 1: 1.12 : 3.07 with water-cement ratio of 0.5 was adopted for a curing period of 7, 14, 28, 60 & 90 days. The result showed that the compressive strength decreased as the percentage of RHA increased. At 90 days, compressive strength of 34.12, 29.70, 28.30, 26.67, 24.48, 23.96 and 23.42N/mm2 was recorded for 0, 5, 10, 15, 20, 25 and 30% replacement level respectively. It was recommended that further work should be investigated to check for the suitability of partial replacement of other grades of Nigerian cement with RHA in concrete.
The influence of cement fineness on the structural characteristics of normal concrete
Authors: Ehikhuenmen S O , Igba U T , Balogun O O , Oyebisi S O
Published: November 2019

This research presents the influence of cement fineness on the structural characteristics of normal concrete. The cement was divided into different fineness zones (150 µm – 7 5µm, 75 µm – 45 µm and 45 µm – 0 µm). Thirty (30 Nos.) cement mortar cubes, 54 Nos. of 150 x 150 x 150 mm concrete cubes and 36 Nos. of 150 x 300 mm cylinder specimens were cast, cured by immersion and tested at 3, 7, 14, 21, 28 and 45 days. A concrete mix ratio of 1:2:4 (Cement: Fine aggregate: Coarse aggregate) with water/cement ratio of 0.5 was used. The results reveal that an increase in the fineness of cement particle led to an increase in workability. The setting times (initial and final setting time) reduces progressively as the cement fineness is increased from 175mins (initial setting time) for sizes 150 µm – 75 µm to an initial setting time of 140mins for sizes 45µm - 0µm. The final setting time also reduces from 300 mins to 240 mins as the cement fineness is increased. The tensile and compressive strengths recorded an increase due to the increase in cement within the concrete matrix. It was concluded that the finer the cement particle the greater the concrete strength.
On the dynamic properties of metamaterials in civil engineering structures
Authors: Oyelade A O , Sadiq O M , Ogundalu O A , Ojoko N K
Published: November 2019

Metamaterials have a foundation in electromagnetics, and the unique properties of these metamaterials have found wide applications in acoustics and electrodynamics disciplines. By exploring local resonant effect of the included aggregates in the concrete mix with ellipsoidal coating rubber, a new elastic metamaterial called metaconcrete is formed. The metaconcrete with anisotropic effective dynamic mass density is determined as functions of frequency numerically. This metaconcrete has unique properties that can prevent earthquakes, shock and other disturbances at a targeted frequency.
The use of recycled concrete aggregate for concrete production incorporating calcined clay as pozzolanic admixture
Authors: Olofinnade O M , Oyawoye I T , Ogara J I , Ede A N , Ndambuki J M , Akinwumi I I , Ajao A M
Published: November 2019

Concrete is the most widely used construction material thereby required a lot of raw resources to keep up with its demand. This leads to depletion of raw resources as well as a continuous build-up of demolished concrete wastes (DCW). In most developing nations like Nigeria, the usual way of disposing these DCW is landfilling. However, recycling has become a viable options for conserving the raw resources and reducing greenhouse gases. This study examines the alternative way of reusing concrete wastes for production of fresh structural concrete. The DCW was obtained from the demolition of an existing concrete building and were treated by soaking in water to help reduce the amount of adhered mortar. A mix ratio of 1:1:2 was adopted with a water-cement ratio of 0.25 to attain a relatively high strength concrete and superplasticizer was added to ensure workable mixes. The recycled aggregates (RCA) were used as partial and complete substitute for natural coarse aggregates in percentages of 0, 20, 40, 60, 80 and 100%, while calcined clay was added as pozzolanic admixture into the mixes at 15% and 20% partial replacement for cement. Tests carried out include the physical characterization of the constituent materials and the compressive strength of the hardened concretes were determined after 7, 14 and 28 days of curing in water using cubes of 100 mm × 100 mm × 100 mm. Results showed that the recycled concrete aggregates has high water absorption due to its porous interface. Moreso, results clearly indicate a continual decreasing trend in the compressive strength as the percentages of the RCA increases, however, a significant increase in compressive strength was observed when calcined clay was added as substitute for cement thereby improving the strength development of concrete.
Investigation of the effect of alkali silica reaction (ASR) on properties of concrete pavement admixed with cow bone ash (CBA) by electrical resistivity test
Authors: Adanikin A , Falade F , Olutaiwo A O , Faleye E T , Ajayi A J
Published: November 2019

The use of concrete in road pavements construction in view of its durability and cost effectiveness over time have gained momentum. Cement concrete pavements however suffer deterioration due to Alkali-Silica Reaction (ASR). This study therefore investigates the use of Cow Bone Ash (CBA) in mitigating the effect of ASR using electrical resistivity test (schlumberger array probe method). The results are then compared with American Society for Testing and Materials (ASTM) standards and relevant literatures. The result of the study showed that the average resistivity at 0%, 5%, 10%, 15%, 20% and 30% CBA replacement are 298.87 Ωm, 306.23 Ωm, 215.02 Ωm, 489.31 Ωm, 382.34 Ωm and 272.53 Ωm respectively. This indicates that the peak resistivity is obtained at 15% CBA replacement which is the optimal replacement level for ASR inhibition in the concrete. The result also shows that the concrete samples are corrosion free with the least resistivity value on the 7thday at 30% CBA addition (163.03 Ωm) and the maximum value at 20% CBA addition on the 56thDay (1069.54 Ωm). The study concluded that ASR and reinforcement corrosion can be effectively controlled between 15% and 20% cement replacement by CBA in concrete/rigid pavements.
Utilization of marble dust powder in concrete
Authors: Ofuyatan O M , Olowofoyeku A M , Obatoki J , Oluwafemi J
Published: November 2019

The economic costs of construction have become largely unbearable today. In a bid to mitigate these costs, civil engineering faculties and stakeholders across the world have endeavoured to produce recyclable and resource saving concrete for construction purposes. Most of the environmental problems are caused by the deposit of waste to the environments in which marble shaping is part. Both stone slurry and solid wastes are generated from the marble stone slurry and with the huge discharge of marble waste locally, emphasizes has been placed on the reuse of the waste material. This research investigates the utilization of marble dust powder in concrete, where marble dust at varying percentage (0%, 15%, 25% & 35%) with replacement by sharp sand was added in M15 grade and water cement ratio 0.50 was kept constant in the concrete mixes. The quality, performance and reliability of the concrete where tested by the compressive and split tensile strength of 7, 21, 28 and 56 curing days. The results of the laboratory work showed that marble dust powder replacement with cement increased in strength up to 25% for both resistance to compressive load and tensile strength of concrete.
Rheology of slag-based geopolymer concrete using corncob ash as a pozzolanic material
Authors: Oyebisi S , Ede A , Olutoge F , Igba T , Ramonu J
Published: November 2019

This study examined the rheology of slag-based geopolymer concrete (GPC) incorporated with corncob ash (CCA). In an attempt to sustain an effective way of recycling our waste products and remedying land, water and air pollution, the study harnessed both ground granulated blast furnace slag (GGBFS) and corncob ash (CCA) as sustainable binders. In addition, sodium hydroxide (NaOH) solution and sodium silicate gel (Na2SiO3) were used as alkaline liquid. Method of volume by batching was adopted where GGBFS was replaced by CCA in 0, 20, 40, 60, 80, and 100%. The paste normal consistency was used to prepare the specimens for both initial and final setting times of the fresh concrete. However, slump and compacting factor values on the freshly made concrete were determined on both grade 30 MPa and grade 40 MPa concretes using the activation of 12, 14 and 16 molar concentrations of NaOH pellets. The experimental results show that the initial and final setting times increased with increasing CCA content; while the slump, compacting factor tests also increased with increasing CCA content. On the other hand, the workability of GPC reduced with increasing grade of concrete and molarity of NaOH solution. The study finding is beneficial in that fresh concrete remains workable for longer periods, thus resulting in lesser joints. It is also advantageous especially in hot weather conditions.
Effect of metallic fillers on the hardness of polystyrene composites: An experimental investigation
Authors: Abdulkareem S A , Amosa M K , Adeniyi A G , Magaji M M , Ajibola R A
Published: November 2019

In this study, the effects of composite thickness (2.5-7.5 mm), filler content (15-45%w/w) and particle sizes (20-100 µm) on the hardness of Polystyrene metal composites were examined. The metals comparatively considered were aluminium particles and iron fillings. It was observed that smaller metal particle sizes in the composite matrix and greater filler proportions will lead to improvement in hardness. Composite thickness did not have a significant effect on the hardness of the metal composites. PS-Al composite is harder than PS-Fe composite with the optimal hardness being 43.7 and 11 respectively. The factor levels that will optimise hardness for PS-Al composite are thickness of 7.5 mm, filler of 39% and particle size of 20 µm. For PS-Fe composites they are thickness of 5.9 mm, filler of 45% and particle size of 34µm. The metallic composites (PS-Al and PS-Fe) exhibited contrasting mechanical strength when viewed under SEM with a homogenous micro-structure of high interfacial interaction between the metal particles (Aluminium) and the PS resin matrix while the PS-Fe metallic composite under micro-structural analysis displayed relatively moderate to low tensile strength and hardness with weak interfacial interaction between the Iron particles and the PS resin.
Development of natural fibre reinforced polystyrene (NFRP) composites: Impact resistance study
Authors: Abdulkareem S A , Amosa M K , Adeniyi A G , Adeoye S A , Ajayi A K
Published: November 2019

The prevalent global issue on environmental pollution and the growing desire for polymer based composite materials has given rise to increasing research in the production of composite containing natural organic fillers. This study describes the optimization of impact strength of plastic composites developed from polystyrene and natural fibre wastes(sawdust and rice husk) using 3-level-factoral-design via hand lay-up method studying the effect of filler concentration (15 – 45 %), filler size (20 – 100 µm) and alkaline treatment concentration (2 – 6 %) on the impact strength of polystyrene fibre reinforced composite. Models were developed using response surface methodology to predict impact strength of the composite as a function of the process variables investigated. The optimization of the process parameters show that the optimum condition for obtaining high impact strength are 15% filler concentration, 100 µm filler size and 4% alkaline (NaOH) concentration in saw dust filled composite while a filler concentration of 15%, filler size of 31µm and an alkaline concentration of 2% for the rice husk filled composite. The recycled polystyrene in combination with wood dust and rice husk has produced a polymer composite with moderate impact strength applicable in various applications.
Effect of temperature on the compressive strength and sustainability of expanded clay lightweight basalt fiber reinforced concrete
Authors: Chiadighikaobi P C , Alaraza H A A , Emiri D A , Eyo J E
Published: November 2019

Concrete exposure to high temperature is a threat to the concrete which leads to loss of strength and degradation of the concrete. Based on this, it was necessary that the behavior on compression of lightweight expanded clay basalt fiber reinforced concrete (BFRC) be investigated when exposed to high temperature. The parameters and dosages of basalt fiber in lightweight expanded clay concrete have effects on the strength of the concrete. The sustainability of a structure in any environment is of high importance therefore, the types of material used as an aggregate and reinforcement must be durable, trustworthy and with the necessary properties suitable for the structure. The main aim of this paper is focused on the ability of lightweight expanded clay basalt fiber reinforced concrete when exposed to high temperature and tested for compressive strength, not to lose its total strength whereby, creating opportunity for the reuse of the concrete. The method of this research is based on laboratory test and practical review analysis. From the compressive strength, a view on the sustainability of this type of concrete is discussed. In this paper, the two sets of specimens were placed on three temperature ranges in a specific time interval. After, they were tested for compression. From the result, it was seen that expanded clay lightweight basalt fiber reinforced concrete didn’t lose much strength under compressive test after it was exposed to high temperature thereby making the concrete sustainable to high temperature.
Innovation in Construction Materials-A Review
Authors: Bamigboye G O , Davies I , Nwanko C , Michaels T , Adeyemi G , Ozuor O
Published: November 2019

This study was carried out to review different types of available innovative construction materials. It was found that advancement in nanotechnology, use of mineral admixture, glass and plastic, biological materials, wood and other construction materials have contributed significantly to the growth of discovery and production of innovative construction materials. The implementation of some innovative construction materials, meets the requirements for sustainability, durability, reliability, safety, cost reduction, increasing quality, better mechanical and physical characteristics, flexibility in extreme conditions and locations, simple assembly and environmentally friendly. Construction materials used to carry out project consumed about 40% of the entire cost of the project in the construction industry. The success stories were recorded in the area of turning industrial and agricultural wastes to wealth. This reviewed paper will enrich the database for innovative materials entering the construction industry.
NFRP strengthening of reinforced concrete beams
Authors: Nwankwo C O , Ede A N , Olofinnade O M , Osofero A I
Published: November 2019

The construction industry is currently the second largest consumer of synthetic FRP products. Increasing environmental awareness and the push for sustainable development fuels the drive to develop high strength natural fibres and bioplastics that can replace the conventional synthetic FRP components. Lignocellulosic plant fibres have considerable high strength and they are currently being used for non-structural applications in various industries. With proper fibre selection, the right fibre orientation, optimal fibre aspect ratio and good interfacial adhesion property between fibre and matrix, natural fibre reinforced polymer (NFRP) composite can be developed for structural applications. This review discusses NFRP composite in terms of its constituents, the fibre-matrix interaction, its manufacture and its use for strengthening of reinforced concrete (RC) beams.
Reliability Evaluation of Compacted Tropical Red Soil Admixed with Waste Wood Ash for Use as Road Construction Material
Authors: Oluremi J R , Yohanna P , Osinubi K J , Eberemu A O , Ijimdiya T S
Published: November 2019

A first-order reliability program (FORM) was applied to evaluate the potential of Tropical Red Soil (lateritic soil) admixed with waste wood ash (WWA) and compacted with British Standard Light (BSL) energy for use as road construction material. Regression models were developed from laboratory data using Mini-tab R15 software which served as limit state equations for the reliability analysis. Using the developed models for compaction characteristics, and a well-known distributions for the related soil parameters, safety indices were calculated considering compaction characteristics (maximum dry density, MDD and optimum moisture content, OMC) as dependent variables and the soil parameters (content of WWA, content of clay, content of silt, content of sand and specific gravity as independent variables). The results revealed that safety index is influenced by alteration in the soil parameters. Results shows that content of clay, content of silt, content of sand and specific gravity are significantly affected by the change in coefficient of variation (COV) and for that reason must be firmly controlled in lateritic soil-waste wood ash (WWA) mixtures compacted with BSL energy for use in road pavement as sub-base material. It was evident from the safety index that WWA content has little effect as its value almost continued unchanged at all COV values used. Stochastically, the BSL energy used did not yield satisfactory safety index value of 1.0 as recommended by the Nordic Committee on Building Regulation. Hence, higher energy level with better additives having higher potency such as cement, lime or bitumen is suggested to model compaction characteristics of lateritic soil-waste wood ash (WWA) mixtures for road pavement purpose as sub-base material for 10-100% variation in COV.
Performance evaluation of hot mix asphaltic concrete incorporating cow bone ash (CBA) as partial replacement for filler
Authors: Modupe A E , Olayanju T M A , Atoyebi O D , Aladegboye S J , Awolusi T F , Busari A A , Aderemi P O , Modupe O C
Published: November 2019

Given the current realities of incessant pavement distresses frequently experienced on Nigerian highways due to axle loads from heavy-duty vehicles, coupled with the menace of grave environmental pollution from abattoir solid wastes such as Cow-bones, the mechanistic properties of Cow Bone Ash (CBA) as partial replacement for filler in the production of asphaltic concrete via the Marshall Mix Design Method and Artificial Neural Networks (ANN) were investigated in this research. The conventional filler was partially replaced with CBA at 2.5%, 5%, 7.5%, 10%, 20%, 30%, 40% and 50% respectively, in the total mix. Sequel to the production of the bituminous concrete at the various proportions, the samples were submerged in water, in a water bath for 30 minutes at a temperature of 105° before conducting Marshall Stability and flow tests. Results revealed that the stability and flow of asphaltic concrete containing the CBA were greater than that of the concrete containing the conventional filler. Furthermore, the physical and volumetric properties of the mix also improved as CBA was observed to be finer than the conventional quarry dust, hence reduced the voids present in the mix and stiffened the bitumen film on the aggregate particles. The results obtained further showed that the conventional filler (quarry dust) can be replaced partially with CBA up to 50%. The ANN Model employed was trained and tested by quick propagation (QP) algorithm amongst others such as the Incremental Back Propagation (IBP), Batch Back Propagation (BBP), Levenberg Marquardt (quasi Newton) and genetic algorithm (GA). QP gave the least Root Mean Square Error (RMSE) at the shortest time. The statistical values obtained showed that the ANN model was able to efficiently study and predict the experimental data.