Engineering Commons^™

Concrete Mix Design Using Abrams And Bolomey Methods, Salem Abdelgader, Marzena Kurpinska, Hakim Abdelgader, Jamal Khatib

BAU Journal - Science and Technology

This research studied concrete design methods. To design concrete using two methods, including the Abrams law and the modified Bolomey method. Concrete with assumed compressive strength 25, 30, 35, 40, and 45 MPa was researched. The research was conducted in the laboratory using two types of samples: cubic 15x15x15cm for compressive strength tests and cylinders ϕ-15cm, h-30cm for the splitting strength tests using the Brazilian method.

The analysis of the cement content in the composition of 1m3 of the mixture showed very large differences depending on the calculation method used. The cement content calculated according to the Abrams method ranged …

Production Of Low-Cost Self-Consolidating Concrete (Scc) Using Manufactured Aggregates, Rabab Raydan, Farah Chamseddine, Ali Jahami, Oussama Baalbaki, Jamal Khatib, Adel Elkordi

BAU Journal - Science and Technology

Limitations to the sources of aggregates and the unavailability of sand is becoming a problematic issue for concrete production. A novel technology of manufactured aggregates can produce well graded round aggregates that can substitute natural aggregates while maintaining the same characteristics needed and preserving the resources. Self-Consolidating Concrete (SCC) using manufactured aggregates is assessed in this experimental work to understand the variability of workability properties and mechanical properties with the changes in w/c ratio and percentages of Coarse Aggregates and Manufactured Sand to Natural Sand in order to choose the best mixture that satisfies an adequate overall performance. Targeting compressive …

New Type Of Lightweight Aggregate For Use In Structural Concrete, Jamal Khatib, Ali Jahami, Oussama Baalbaki, Adel Elkordi

BAU Journal - Science and Technology

This research studied the utilization of municipal solid waste incineration bottom ash (MSWI-BA) in lightweight coarse aggregate (LWC) production. A special method was followed to prepare the new aggregate to fully replace the normal aggregates (NWA) in concrete. The mechanical properties such as compressive strength, tensile strength, and elasticity modulus were investigated for the LWC concrete. Then, two beams were prepared; one from LWC and the other from NWC. The structural performance of beams made up of lightweight aggregates compared to normal aggregates was investigated. The results showed that this type of aggregates led to a 20% reduction in concrete …

Uncertainty Of The Ultrasonic Method For Determining The Strength Of Concrete, Ortagoli Sharipovich Hakimov, Zamira Khudoyberdiyevna Ernazarova

Chemical Technology, Control and Management

The issues of measuring the strength of concrete by the method of surface sounding by ultrasound are considered. A measurement model and formulas for estimating the total standard measurement uncertainty, information about the standards used, measurement tools and methods, and environmental parameters are given. Information about the estimation of uncertainty in the form of "eight steps", such as: measurement task; mathematical model of measurement; analysis of input values; observation results; correlations; uncertainty budget; expanded uncertainty; measurement result. It has been established that the uncertainty of type B of the ultrasonic method for determining the strength of concrete is much less …

Effect Of Using Cathode-Ray Tubes (Crt) Waste Glass On Concrete Properties, Jad Bawab, Jamal Khatib, Ali Jahami, Said Kenai, Adel Elkordi

BAU Journal - Science and Technology

Cathode-ray tube (CRT) glass is a hazardous material that should be responsibly managed when disposed. One of the possible options for recycling CRT waste glass is using it as fine aggregates in concrete for its richness in silica. For the aim of evaluating concrete with this material, four mixes with replacement levels of 0%, 10%, 20% and 30% are prepared. Workability, hardened density, ultra-pulse velocity, compressive strength, tensile strength, and static modulus of elasticity were examined. Experimental results showed that the use of CRT improved properties of concrete at certain replacement levels. CRT glass improved the workability of concrete where …

Concrete Mix Design Using Simple Equations, Hakim Abdelgader, Ramadan Suleiman, Abdalla Adam, Jamal Khatib

BAU Journal - Science and Technology

The behaviour of concrete, whether fresh or hardened, depends basically on the behaviour of its components and the relationship between them, therefore, obtaining a concrete with certain properties depends fundamentally on the concrete mix design. Concrete mix design generally includes two main steps: 1-Selection of the main components suitable for the concrete (cement, aggregate, water, and additives); 2-Determination of more economical mix ratios to fulfil the workability, strength and efficiency requirements. Currently, there are many international methods locally approved for mix designs. They are all related to each other, they give relatively the same quantities of the mix components and …

Pod In Concrete Performance Assessment, A Manoj

Manipal Journal of Science and Technology

The quality of ingredients and their quantity in the concrete mix decide the performance level. As the number of variables on which concrete performance depends increases, it is essential to identify those, to which the performance characteristics are sensitive. Efficacy of Proper Orthogonal Decomposition (POD) in the visualisation of patterns in data, its utility in the identification of crucial variables, prediction of performance levels, and generation of performance indices have been discussed and illustrated.

About The Technology Of Making Reinforced Concrete Sleep By Heating Concrete At Low Temperature, Turgunbaev Urinbek Jamolovich, Movluda Umirova

Journal of Tashkent Institute of Railway Engineers

The article discusses the properties of cement stone with the use of complex chemical additives to improve the technology for the production of sleepers from prestressed concrete. With the use of superplasticizer, the volume of intergranular space and, consequently, capillary porosity, which is a determining factor for both strength and frost resistance and corrosion resistance of concrete, are significantly reduced. Also, during thermo-wet processing, at a temperature of 40 ° C, there was no decrease in the strength of cement stone and sufficient strength at the initial stage of the curing period, 36 MPa with the addition of Glenium 27 …

A Review On The Use Of Vegetable Oil And Its Waste In Construction Applications, Ahmed Chamaa, Jamal Khatib, Adel Elkordi

BAU Journal - Science and Technology

The generation of waste materials is causing an impact on the environment due to many reasons including the effect on human health and decrease in landfill space. Of these waste materials is the waste cooking oil. There are large amounts of waste vegetable oil generated in the world and most of it is disposed of in the sewer system which can cause problems when treating wastewater. This paper is a review of literature on the use of vegetable oil (VO) and waste vegetable oil (WVO) as chemical admixtures in construction materials. The construction materials include mainly concrete and pavement. The …

Production Of Fire-Resistant Concrete Based On Technogenic Waste, Uzmonjon Turgunaliyevich Yusupov

Journal of Tashkent Institute of Railway Engineers

The article notes that at present, with the development of the construction industry, the need for fire-resistant concrete is also increasing. In increasing the volume of construction, concrete and other components are some of the resources available at the price of finished objects achieved through cost reduction. It is determined that the developed fire- and heat-resistant concrete, prepared according to the technological requirements developed by us and the established standards, will provide the facility with reliable fire safety and longevity

Features Of Hydration Process, Structure Formation And Curing Processes Of Mono And Polymineral Cement In The Presence Of Additives Of Solid Waste Of Soda Production, Nargis Shamadinova, Gulnora Abdukadirovna Tokhtakhunova Phd, Temur Azimovich Atakuziev, Shakhnoza Saidanvarovna Rakhimjanova

Chemical Technology, Control and Management

The influence of the additive of solid waste of soda production (SWSP) on the content of -C₂S and C₃S in cement studied. It was found that SWSP affects the density of the aluminum-containing minerals C₃A and C₄AF, in addition, in the presence of gypsum, their plasticizing properties improved. The introduction of SWSP additives during grinding of clinker intensifies the grinding process and made it possible to obtain a more plastic cement. It was proved that SWSP with CaCl₂ content can be used as an additive to concrete and cement mortars - …

Method Of Calculation Of Self-Stressed Concrete Slabs Supported Along The Contour, S.S. Salixanov

Journal of Tashkent Institute of Railway Engineers

The paper presents the developed method for calculating the contour-supported slab of self-stressed concrete. Reinforced concrete slab on the tension cement replaces the traditional construction of the bridge. In this article, in order to exclude reinforcement, the problem of determining the stress-strain state of self-stressed concrete slabs supported along the contour is considered. The values of stresses in the upper and lower faces of the concrete slab, as well as the bending moment in the middle section of the slab

Using Of Proper Pavement Material For The Intersections With Slow-Moving Traffic, Bekim Selimi

International Journal of Business and Technology

Use of proper pavement material for some of intersections need special attention by road designers. At Camp Bondsteel-Kosovo on 2002 were built four road intersections using the concrete as pavement material. Heavy and slow-moving trucks that are turning or accelerating exposed these intersections to some of the highest stress level. After some years this intresections start deteriorating on their surface due to friction. The concrete pavements did not survive this period of usage and after eight years were removed and replaced with asphalt pavements. After more than seven years, the asphalt has shown minor distress but is still in good …

Reducing The Porosity And Sealing Cracks By Using Crystalline Admixture In Conventional Concrete, Visar Krelani, Liberato Ferrara

International Journal of Business and Technology

There is a continuous increase of quality on civil engineering materials in developed countries and parallel increase of need for new constructions in developing countries. Professional community should propose solutions for the durability that can resist in different severe environments. The most important factor that can affect concrete durability is represented by the pore distribution. Transport properties can take place through the porous network inside the cementitious composites and the aggregates interface, permitting the ingress of aggressive agents damaging concrete function intrinsically as a material and the wellfunctioning of the entire structure. The use of a crystalline admixture during the …

Prediction Of Punching Shear Capacity Of Two-Ways Frp Reinforced Concrete Slabs, Ilker Fatih Kara, Besian Sinani

International Journal of Business and Technology

An innovative solution to the corrosion problem is the use of fiber-reinforced polymer (FRP) as an alternative reinforcing material in concrete structures. In addition to the non corrodible nature of FRP materials, they also have a high strength-to-weight ratio that makes them attractive as reinforcement for concrete structures. Extensive research programs have been carried out to investigate the flexural behavior of concrete members reinforced with FRP reinforcement. On the other hand, the shear behavior of concrete members, especially punching shear of two-way slabs, reinforced with FRP bars has not yet been fully explored. The existing provisions for punching of slabs …

Chloride-Binding Isotherms In Concrete Submitted To Non-Steady-State Diffusion-Migration Model, Wen-Hu Tsao, Ming-Te Liang, Ta-Peng Chang

Journal of Marine Science and Technology

We propose a mathematical non-steady-state, time/depth dependent diffusion-migration model based on the modified Fick’s second law of diffusion. It considers the effects of different chloride binding mechanisms for the transport process of chloride ions diffused in a porous concrete on the variation of its chloride profile. Four different chloride-binding isotherms, i.e., no binding, linear binding, Langmuir binding and Freundlich binding, together with the time/depth dependent chloride diffusivities are investigated. Results of this study show that the variations of amounts of available free chloride ions in the solution of saturated concrete resulting from different chloride-binding isotherms have significant effects on the …

Carbonation Resistance Of Concrete With Mortar Coating, Wen-Hu Tsao, Ming-Te Liang, Nai-Ming Huang, Ke-Hung Liao

Journal of Marine Science and Technology

The principal purpose of this paper was theoretically to study the carbonation resistance of a semi-infinite medium which concrete has a mortar coating having diffusion properties different from those of the rest of the medium. The analytical solution of a semi-infinite composite medium was used to predict the time required for subsidence due to concrete with mortar coating. The inaccurate analytical solution was published in previous books. Thus, the analytical solution of a semi-infinite composite medium is re-derived in this article. The governing equations without initial and boundary conditions in the previous books are also pointed out. In order to …

Evaluation Of Penetration Depth And Protective Effectiveness Of Concrete-Penetrating Sealer Materials, Sung-Ching Chen, Ran Huang, Hui-Mi Hsu, Si-Yu Zou, Li-Wei Teng

Journal of Marine Science and Technology

Crystal penetrating sealer materials (PSMs) are commonly used on the surface of concrete to protect the surface from damage and thereby extend its service life. Such materials penetrate into existing pores or cracks and form crystals, which block potential paths through which unknown materials could enter and degrade the concrete. In this study, the constituent compounds of a PSM were divided into seven categories, labeled CAT I to CAT VII, and five discrete particle size fractions corresponding to sieve Nos. 30, 50, 100, 200, and 200 were considered. Energy dispersive spectrometry revealed that the constituent elements of the PSM were …

Corrosion Of Rebar Under Carbonation And Salt Environment, Wei-Chung Yeih, Jiang-Jhy Chang, Yu-Ping Huang, Ran Huang

Journal of Marine Science and Technology

In this study, the behavior of reinforced concrete under carbonation and in a salt environment was investigated. Three types of cements- Type I cement, Type II cement and highalumina cement (HAC) - were used to study the influence of cement on reinforced concrete behavior. To simulate chloridecontaminated concrete, 1% NaCl (by cement weight) was added to some groups of specimens. Results revealed that the carbonation released chloride ions from Friedel's salt, which increased the chloride content near the carbonation front. The carbonation rate of HAC concrete was higher than that of Type I and Type II cement concrete. The corrosion …

Effect Of Fly Ash Fortification In The Manufacture Process Of Making Concrete Towards Characteristics Of Concrete In Sulfuric Acid Solution, Asep Handaya Saputra, Muhammad Shohibi, Masatoshi Kubouchi

Makara Journal of Technology

Fly ash is a silica or alumino silica material that can be used as a constituent of cement in the concrete manufacturing process. Utilization of fly ash aims to improve durability and minimize the reduction of concrete’s compressive strength exposed to an acidic environment, which can be achieved through the pozzolanic reaction of fly ash with Ca(OH)2 within concrete. The reduced content of Ca(OH)2 through pozzolanic reaction will minimize the tendency of ettringite formation (compounds that cause deterioration and decrease the compressive strength of concrete). In order to determine the relation between fly ash replenishment into concrete with concrete’s characteristics …

Analytical Model Of Ultrasonic Pulse Velocity Of Waste Lcd Glass Concrete, Chien-Chih Wang, Her-Yung Wang, Shyh-Haur Chen, Chi Huang

Journal of Marine Science and Technology

The purpose of this study is to establish a prediction model for the ultrasonic pulse velocity (UPV) of waste LCD glass concrete and then analyze the results obtained from a series of laboratory tests. The power function is used to perform the nonlinear-multivariate regression analysis of the UPV prediction model, with parameters such as water-binder ratio (w/b), curing age (t) and waste glass content (G). According to the relative regression analysis, the UPV prediction model is developed. The calculated results are in accord with the laboratory-measured data, which are the concrete UPV of various mix proportions. The regression analysis results …

Effect Of Mortar Coating On Concrete Carbonation, Wen-Hu Tsao, Ming-Te Liang, Jiang-Jhy Chang, Nai-Ming Huang

Journal of Marine Science and Technology

The mechanism of the effect of mortar coating on carbonation of concrete is investigated. Theoretical methods of Fick's first and second laws of linear diffusion are used to calculate the carbonation depth of concrete without and with mortar coating, respectively. Theoretical analyses are also done to obtain the carbonation retard coefficients of mortar coating on concrete with surface coatings. A great deal of well organized experimental tests are carried out to verify the values of calculation. The results of present study indicate that the suitable mortar coating on concrete can effectively delay carbonation of concrete. The carbonation depth is inversely …

Bringing To Life The World’S Tallest Structure, Jonathan Weigand

Pursuit - The Journal of Undergraduate Research at The University of Tennessee

Intended as the centerpiece of constructional developments in Dubai, the Burj Khalifa now stands as the tallest building ever constructed. The uniquely designed foundation consists of a concrete raft supported by a cast-in-place pile system protected by waterproofing membrane to inhibit corrosion. The structural design integrates high-performance reinforced concrete and steel and incorporates an engineered “Y” shape that limits the lateral wind pressure on the building. Engineers applied the latest advancements in high-rise technology to develop an optimized construction plan that consisted of segmented tasks that promoted the staff to work at a quick yet manageable pace. This article details …

Sensitivity Analysis Of Time/Depth Dependent Chloride Diffusion Coefficient In Concrete, Yung-Ming Sun, Ta-Peng Chang, Ming-Te Liang

Journal of Marine Science and Technology

This paper presents the results for a sensitivity analysis of the time/depth dependent chloride diffusion model in concrete using differential analysis techniques. Four governing prameters of the model are taken to determine the sensitivity of the chloride diffusion coefficient: the time of exposure, inspecting depth, surface chloride concentration, and chloride concetration at the inspecting point. The results of this sensitivity analysis are discussed in detail, including variations in the diffusion coefficient according to the four parameters and the implications for durability design of concrete structures.

Biodeterioration Of Coastal Concrete Structures By Macro Algae - Ulva Fasciata, Stri Hari Babu Jayakumar, Rama Saravanane, Thirumalai Sundararajan

Journal of Marine Science and Technology

Puducherry is a coastal region in India where the growth of Ulva fasciata (Delile) is very abundant on all marine structures. Though the detrimental effect of this macro algae U. fasciata is a secondary one, its effect has to be investigated. To know its effect, the basic mechanism by which U. fasciata deteriorates concrete structures has been highlighted. To ascertain its detrimental effect on coastal concrete structures, M20 grade concrete cubes were casted and immersed in the coastal area where there is abundant growth of U. fasciata. In addition laboratory simulation has been carried out. Concrete samples collected from the …

Penetration Lag Of Chloride Diffusion Through Concrete Plate Based On Advancing Model, Chih-Hsing Wang, Cho-Liang Tsai, Ching-Chang Lin

Journal of Marine Science and Technology

The solution, based on Neumann's theory, for the content distribution of a diffusion material in a semi-infinite medium is applicable for the case in which a diffusion material diffuses from one side of a plate medium to the other side. After the diffusion material reaches the other side, the penetration rate of the diffusion material is solved using Fick's diffusion law. In this study, concrete plates are manufactured and submerged individually in special containers with saltwater on one side and freshwater on the other side, and no electric charge is applied. The amount of chloride penetrating the plate is monitored. …

Electrochemical Detection For The Corrosion Of Reinforcing Steel In Concrete During Immersion And Drying Cycles, Bing-Li Jia, Fa-He Cao, An-Na Chen, Jian-Qing Zhang

Journal of Electrochemistry

The corrosion behavior of reinforcing steel in concrete under dry-wet cycle condition has been studied by electrochemical noise(EN) compared with the electrochemical impedance spectroscopy(EIS),SEM micrographs and EDS.The statistical method has been employed to analyze the EN data of reinforcing steel in concrete,which revealed three different corrosion stages of reinforcing steel in concrete,including the dissolution of the passive film,the active corrosion and the cumulation of corrosion product.The wavelet transform has also been employed,which indicated that steel in concrete with pH 1 is associated with uniform corrosion,while steel in concrete with pH 3 and pH 7 are associated with localized corrosion,such as …

Studied Corrosion Behaviors Of Reinforcing Steel In Concrete By A Single-Dimensional Array Electrode, Lan-Qiang Li, Shi-Gang Dong, Rong-Gui Du, Chang-Jian Lin

Journal of Electrochemistry

A single-dimensional array electrode was developed as a new electrochemical technique to image corrosion potential,galvanic current and polarization curves of reinforcing steel in concrete during corrosion process.Combining with the polarization behavior for each micro-electrode,the interactions between corrosion macrocell and corrosion microcell of the steel in concrete were evaluated.It was noticed that the corrosion macrocell and microcell occurred independently in difference regions at the initial stage of corrosion.The corrosion macrocell current can be in situ followed by corrosion potential imaging.The corrosion propagation of steel in concrete is closely related to the interactions between corrosion macrocell and corrosion microcell.

Effect Of Naphthalene Water Reducer On Corrosion Behavior Of Reinforcing Steel In Concrete, Yu-Ming Tang, Jie Zhang, Yu Zuo

Journal of Electrochemistry

The influence of naphthalene water reducer on corrosion behavior of reinforcing steel in concrete was studied by the methods of corrosion potential measurement,linear polarization and EIS test.The values of concrete resistance(Rc) and polarization resistance(Rp) of the samples with naphthalene water reducer were higher than those without naphthalene water reducer,especially in the concrete with 0.2 percent naphthalene water reducer.A suitable amount of water reducer can improve the pore structures of concrete,increase the concrete compactness and impermeability,and decrease corrosion rate of rebars in concrete.

Effect Of Cracks On Corrosion Of Rebar In Concrete Studied By Wire Beam Electrode, Guo-Xi Li

Journal of Electrochemistry

The effects of crack and ethanolamine on corrosion of rebar in concrete were studied by measuring the distribution of corrosion potential and polarization resistance of iron wires in 10% NaCl solution.The results showed that the diffusion of water,oxygen and chloric ion toward concrete was accelerated by the crack which intensified the nonuniform corrosion of iron wire with the regions near to crack as anode and the uncracked regions as cathode.Ethanolamine could diffuse into the body of concrete and absorb on the surface of iron wire,which reduced iron corrosion evidently and successfully inhibited the nonuniform corrosion caused by crack without changing …