A new formulation for strength characteristics of steel slag aggregate concrete using an artificial intelligence-based approach

Studies examining nanoparticles (NPs) and hazardous elements (HEs) contained in suspended sediments (SSs) are vital for watershed administration and ecological impact evaluation. The biochemical consequence of titanium-nanoparticles (Ti-NPs) from SSs in Colombia's Magdalena River was examined utilizing an innovative approach involving nanogeochemistry in this study. In general, the toxicity and the human health risk assessment associated with the presence of some Ti-NPs + HEs in SSs from riverine systems need to be determined with a robust analytical procedure. The mode of occurrence of Ti-NPs, total Ti and other elements contained within SSs of the Magdalena River were evaluated through advanced electron microscopy (field emission scanning electron microscope-FE-SEM and high resolution transmission electron microscope-HR-TEM) coupled with an energy dispersive X-ray microanalysis system (EDS); X-Ray Diffractions (XRD); and inductively coupled plasma-mass pectrometry (ICP-MS). This work showed that enormous quantities of Ti-NPs were present in the river studied and that they displayed diverse eochemical properties and posed various possible ecological dangers. Ti-NP contamination indices must be established for measuring the environmental magnitudes of NP contamination and determining contamination rank among rivers. Finally, SS contamination guidelines must be recommended on an international level. This study contributes to the scientific understanding of the relationship of HE and Ti-NP dynamics from SSs in riverine systems around the world.Keywords Titanium-nanoparticles, Rutile and Anatase nano-minerals, Particle mode of occurrence, Size-dependent properties, Nanomineral–water interface, Surface particle geochemistry

Reinforced concrete deterioration caused by contaminated construction water: an overview

Over the years, there were cases of building failures in most developing countries of the world that have led to the loss of lives and property. Yet, most investigations conducted on the causes of building failures have suggested poor design, inadequate supervision, and the use of inferior materials as the factors responsible for the failures. However, not so much emphasis has been placed on concrete mixing water as a contributing factor to the failures. Therefore, this review summarizes the effect of the type and composition of mixing water on the properties of concrete. Different sources of water that can be used to mix concrete were explored, alongside with the effect on fresh and hardened properties of concrete. The fresh properties of concrete, such as setting time and slump, were examined, while the hardened properties focused on the strength and durability of the concrete. A brief statement on the available regulation and standards for mixing water was also reported. This review shows the viability of using water from different sources, such as wastewater, to mix concrete successfully. However, the treatment of some types of water might be required to ensure that excellent strength and durability properties are achieved while preventing any threat to human life and the environment. Area for future research was also suggested, which, among other procedures, could help proffer solutions to the challenge of building failures in developing countries

Estimating strength properties of geopolymer self-compacting concrete using machine learning techniques

There has been a persistent drive for sustainable development in the concrete industry. While there are series of encouraging experimental research outputs, yet the research field requires a standard framework for the material development. In this study, the strength characteristics of geopolymer self-compacting concrete made by addition of mineral admixtures, have been modelled with both genetic programming (GEP) and the artificial neural networks (ANN) techniques. The study adopts a 12M sodium hydroxide and sodium silicate alkaline solution of ratio to fly ash at 0.33 for geopolymer reaction. In addition to the conventional material (river sand), fly ash was partially replaced with silica fume and granulated blast furnace slag. Various properties of the concrete, filler ability and passing ability of fresh mixtures, and compressive, split-tensile and flexural strength of hardened concrete were determined. The model developmentinvolved using raw materials and fresh mix properties as predictors, and strength properties as response. Results shows that the use of the admixtures enhanced both the fresh and hardened properties of the concrete. Both GEP and ANN methods exhibited good prediction of the experimental data, with minimal errors. However, GEP models can be preferred as simple equations are developed from the process, while ANN is only a predictor

Leadership development and sustainable leadership among TVET student

Leadership has become a key component of an organization, management and administration of educational organizations and systems, and this development is reflected in both academic and educational policy statements throughout the English-speaking countries and world over. Governments are investing substantial sums in leadership development because they believe that it will produce better leaders and more effective school system. Individuals are also contributing their own professional development because they think that it will enhance their career prospects and make them better leaders. Without leadership, things will be very difficult and we would have not been here today. Technical and vocational education is one of the organizations that have been enjoying leadership of different types. The importance of leadership in technical and vocational education cannot be overemphasizing, because without proper leadership in TVET programs, the goals which are to prepare people to be self-reliance will not be possible. Therefore, the need for good and perfect leadership has become imperative in TVET development. Effective school leadership has become a dominant theme in contemporary educational reform. Effective leaders are needed to sustain innovation and are the heart of capacity building for school improvement most especially in technical and vocational education and training (TVET) programs that need sustainability for its development

Permeability properties of lightweight self-consolidating concrete made with coconut shell aggregate

Liquid substance intrusion into concrete is one of the issues that gradually damage its phys- ical and structural integrity. The permeability properties of lightweight self-consolidating concrete containing coconut shell aggregate was investigated in this study. A partial replace- ment of crushed rock (granite) with coconut shell from 0 to 100% in step of 25% was considered for the mixtures. Rice husk ash (RHA) and Silica fume (SF) were considered for developing binary and ternary blended self-consolidating concrete with total powder content of 450 kg/m3 and 550 kg/m3. The testing of concrete involved the saturated water absorption, sorptivity and chloride ingress, which were used to examine the permeability properties of the concrete developed. The laboratory investigations showed encouraging results with better performance up to 75% replacement of crushed granite with coconut shell aggregate

Fresh and hardened properties of concrete incorporating binary blend of metakaolin and ground granulated blast furnace slag as supplementary cementitious material

The growing demand for cement has created a significant impact on the environment. Cement production requires huge energy consumptions; however, Pakistan is currently facing a severe energy crisis. Researchers are therefore engaged with the introduction of agricultural/industrial waste materials with cementitious properties to reduce not only cement production but also energy consumption, as well as helping protect the environment. +is research aims to investigate the influence of binary cementitious material (BCM) on fresh and hardened concrete mixes prepared with metakaolin (MK) and ground granulated blast furnace slag (GGBFS) as a partial replacement of cement. +e replacement proportions of BCM used were 0%, 5%, 10%, 15%, and 20% by weight of cement. A total of five mixes were prepared with 1 :1.5 : 3 mix proportion at 0.54 water-cement ratios. A total of 255 concrete specimens were prepared to investigate the compressive, tensile, and flexural strength of concrete after 7, 28, and 56 days, respectively. It was perceived that the workability of concrete mixes decreased with an increasing percentage of MK and GGBFS. Also, the density and permeability of concrete decreased with an increasing quantity of BCM after 28 days. Conversely, the compressive, tensile, and flexural strength of concrete were enhanced by 12.28%, 9.33%, and 9.93%, respectively, at 10% of BCM after 28 days. +e carbonation depth reduced with a rise in content of BCM (up to 10%) and then later improved after 28, 90, and 180 days. Moreover, the effect of chloride attack in concrete is reduced with the inclusion of BCM after 28 and 90 days. Similarly, the drying shrinkage of concrete decreased with an increase in the content of BCM after 40 days

A review of the engineering properties of metakaolin based concrete: towards combatting chloride attack in coastal/ marine structures

Changing human lifestyle and increasing urbanisation are contributory factors to the high demand for concrete construction materials across the globe. With the imminent developments in the unpopulated marine/coastal zones, higher installation of concrete facilities is still expected. However, poor design and construction procedures coupled with inadequate materials selection and exposure to aggressive environmental conditions, such as chloride laden environments, often result in the reduced aesthetic and structural performance of concrete. Deterioration of reinforced concrete structures located in a coastal/marine setting can influence the safety, economic, and sustainability aspects of society. Hence, there is an increased need for alternate binder systems with the ability to reduce the effects of chloride attack in concrete. 1is paper presents a critical review of the engineering properties of metakaolin (MK) based concrete exposed to chloride attack. 1e key advantages and limitations of using MK for concrete production purposes were outlined and evaluated. Areas for future research were also highlighted in this paper. Based on the favourable 28-day compressive strength (73–84 MPa) and durability performance documented across the numerous past year studies that were reviewed, it can be concluded that MK is a viable alternate binder material for combatting chloride attack in coastal/marine concrete structures. 1is, in conjunction with its lack of chemical CO2 emissions, proves that MK can be used to improve the serviceability and sustainability states of marine structures. 1e viewpoint of this review will guide concrete constructors and researchers on a possible framework for the utilisation of metakaolin for enhancing durability concrete in aggressive environments

Komitmen organisasi, kepuasan kerja dan prestasi kerja dalam kalangan pensyarah universiti di Kota Batam Indonesia

Universiti adalah salah satu tempat bagi meningkatkan kualiti sumber manusia. Pembangunan pendidikan dalam peringkat universiti di Kota Batam khususnya telah melibatkan pelbagai pihak iaitu pensyarah, universiti, masyarakat serta pelbagai organisasi pendidikan lain. Pencapaian prestasi sebuah universiti merangkumi prestasi para pensyarah mahupun pihak pentadbir yang terdapat di universiti dan menjadi penting untuk diperhatikan. Kurangnya kajian mengenai komitmen, kepuasan kerja dan prestasi kerja dalam kalangan pensyarah di peringkat Universiti. Kajian yang ada biasa ianya dilakukan di sektor syarikat sahaja, sehingga kajian ini perlu dilakukan dalam kalangan pensyarah di peringkat universiti. Objektif dalam kajian ini bagi memastikan hubungan dan sumbangan komitmen organisasi, kepuasan kerja dan prestasi kerja pensyarah. Data dikumpul menggunakan instrumen soal selidik melibatkan sampel kajian seramai 179 orang pensyarah universiti di bandar Batam, Indonesia iaitu Universiti Putera Batam, Universiti Batam dan Universiti Riau Kepulauan. Data-data kajian dianalisis menggunakan SPSS. Hasil kajian didapati bahawa, komitmen dan prestasi kerja, komitmen dan kepuasan kerja, kepuasan kerja dan prestasi kerja, komitmen dan kepuasan kerja terhadap prestasi kerja mempunyai hubungan positif dan signifikan. Hasil dapatan kajian dapat digunapakai sebagai acuan bagi keperluan institusi, akademisi, dan praktisi dalam membuat standar evauasi. Selain itu, bagi pihak universiti ianya perlu mengambil kira hubungan komitmen organisasi dan kepuasan kerja, kepuasan kerja dan prestasi kerja, serta komitmen organisasi dan prestasi kerja. Selain itu perlu pula mengambil kira hubungan komitmen organisasi dan kepuasan kerja terhadap prestasi kerja, dan faktor lain diluar kajian yang dijalankan seperti faktor demografi, kepengurusan, kepimpinan, budaya organisasi dan lain-lain

Exploring engineering properties of waste tire rubber for construction applications

A sizeable amount of tire rubber waste is generated due to the increasing number of road automobile users all over the world. The accumulation of this waste in the open area poses environmental threats and therefore requires suitable treatments. The use of waste obtained from tire rubber as a construction material could contribute to a circular economy, while at the same time be an eco-friendly method of minimizing the depletion of raw materials used for the development of building materials. This study aims to show the impact of crumb rubber (CR) on the properties of concrete. This review covers the environmental consideration of fresh and hardened properties of composites developed using waste tires. The results show that the plastic nature of CR with suitable admixture led to increasing slump value and consequently enhanced the CR concrete workability

Sustainable composite development: Novel use of human hair as fiber in concrete

In the present era, to recycle waste and to reduce environmental pollution is the main objectives of sustainable development. Many researchers are working on new techniques and thinking for innovation in the field of concrete technology by utilizing the waste material in concrete. This research aims to check the effect of a human hair (waste material) as fiber on the fresh, physical and mechanical properties of concrete with 0%,1%, 2%, 3%, and 4% of human hair by volume of cement. In this regard, a total of 180 concrete specimens (cubes, cylinders, and prisms) was made and cured after 7th, 28th, and 90th day. The result indicated that the compressive strength was enhanced by 8.15 % at 1% human hair after 28 days as indirect tensile strength and flexural strength were improved by 21.83 % and 12.71 % at 2% of human hair after 28 days, respectively. Also, the density of concrete gets reduced with rising in the content of human hair, and water absorption is improved, as the content of human hair increases after 28 days, respectively. Besides, the modulus of elasticity increased with the inclusion of human hair after every curing period, and drying shrinkage of concrete is minimized with the addition of human hair as fibers in concrete at 40 days. The slump value was reduced as the content of human hair increase