Engineering Commons^™

Assessment Of The Mechanical And Durability Characteristics Of Bio-Mineralized Bacillus Subtilis Self-Healing Concrete Blended With Hydrated Lime And Brick Powder, Mohd Abu Bakr, Birendra Kumar Singh, Ahmed Farouk Deifalla, Shatrudhan Pandey, Ahmed Hussain, Sahir Sultan Alvi, S.M. Mozammil Hasnain

Civil Engineering Faculty Publications and Presentations

Highlights

• The present paper studied the effect of biomineralization on the properties of HBr concrete.

• Strength and durability properties are improved by calcite precipitation produced by bacteria.

• CaCO3 Precipitation was confirmed in the microstructure analysis through FESEM and EDS.

Abstract

Cement is the main constituent of the concrete structure. Using rejected brick as pozzolana in replacement of cement reduced the utilization of natural resources, conserved the environment, and controlled waste disposal. Hydrated lime has been utilized as a chemical additive to improve the pozzolanic reaction of finely ground waste brick particles. This research investigates the process of biomineralization to enhance …

Physico-Mechanical Characterization Of Prototype Earth Block Material For Constitutive Modeling, Erika Lorena Rengifo-López

Theses and Dissertations

The comprehensive understanding and experimental characterization of the overall compressive behavior of earth masonry block materials, such as compressed and stabilized earth blocks (CSEBs), are essential for developing analytical and numerical tools to predict the mechanical response and designing earth masonry structures. Furthermore, advancing the understanding of the extent of the influence of testing parameters on the material's response, such as specimen geometry, is a critical step towards standardization.

CSEBs are produced by compressing a mixture of soil, water, and a stabilizer (e.g., Portland cement). The heterogeneity of the material accrues from the variety of soil particle morphology and potential …

Evaluating The Effects Of Curing Methods On Bcsa Cement Concrete, Hannah Allen

Civil Engineering Undergraduate Honors Theses

BCSA cement is a type of cement that makes concrete set up much quicker than typical portland cement concrete. BCSA cement concrete also has a much higher compressive strength than that of portland cement concrete. This study was conducted to determine the effect of different curing conditions on the compressive strength of BCSA cement concrete.

Shear Strength Of Concrete Beams Made With Belitic Calcium Sulfoaluminate Cement, Caleb W. Chesnut

Graduate Theses and Dissertations

The need for a cleaner alternative to portland cement (PC) concrete has led to increasing interest in alternatives to PC. Structural properties of most of these alternative cements are still an open research topic. One promising alternative cement is belitic calcium sulfoaluminate (BCSA) cement. The study presented in this paper investigated the shear strength, long term compressive strength, and carbonation in BCSA cement and PC concrete beams. A total of twelve eight-foot long beams were made; eight BCSA cement concrete beams and four PC concrete beams to be tested at various ages depending on cement type. Two beams of each …

The Impact Of Grinding Time On Properties Of Cement Mortar Incorporated High Volume Waste Paper Sludge Ash, Ali A. Shubbar, Monower Sadique, Mohammed S. Nasr, Zainab S. Al-Khafaji, Khalid S. Hashim

Karbala International Journal of Modern Science

Cement is considered a base material in preparing blending mixtures that applying in various projects in the civil engineering field. Nevertheless, the cement production process cause indubitable negative environmental influences such as emitting CO₂. The production of cement produces around 7% of the global CO₂ emissions. Thus, searching for alternate binders in building processes to minimise or substitute cement has been one of the social problems. A by-product or waste products are among the potential alternatives to the mentioned problem. The present investigation involves the consumption of paper sludge ash (PSA) waste as cement replacement to produce …

Using Bcsa Cement To Repair Waterway Transportation Structures, Anazaria Johanis Ortega Gonzalez

Graduate Theses and Dissertations

Many maritime structures (e.g., locks, dams, ports) in the US are either reaching or are past their design lives, and there are limited funds for the necessary maintenance activities which can lead to repairs that requires closures. These structures are not easy to detour and often require dewatering before repairs can be made, closures can cause delays and business-related losses which can have a large effect on the nation’s economy. Thus, it is advantageous to reduce the repair time for maritime structures. BCSA (belitic calcium sulfoaluminate) cement is a promising material to perform this type of repair due to its …

Leveraging Biomimicry And Additive Manufacturing To Improve Load Transfer In Brittle Materials, Ana Paula Bernardo

Graduate Theses and Dissertations

With the emergence of Additive Manufacturing (i.e., 3D printing) in construction, new strategically designed shapes can be created to improve load transfer through structural members and foundations. Cross-sections can be optimized to carry load using less material, or even using weaker constituent materials, like soils, which are cheap and abundant. The goal of this research is to investigate the benefits of using cellular patterns which leverage biomimicry in civil engineering applications, since nature has perfectly engineered materials and patterns which carry loads with the least amount of material possible. Most of the periodic cellular work to date has focused on …

The Effect Of Concrete Sample Size In The Compressive Strength Value Of Concrete, Erion Luga, Erion Periku, Paulin Sheperi

UBT International Conference

Concrete is one of the most widely used construction materials. Compressive strength is one of the most important properties of hardened concrete. Different codes use different standards to define the characteristic strength. Albania nowadays is adapting the EN standards, but previously it used to apply the local code KTP. According to KTP standards the concrete samples were cubic specimens of 200mm side length. This study is an attempt to analyse the relation between sample size and compressive strength values of concrete specimens. For this purpose, 4 concrete classes of C8/10, C16/20, C20/25, C30/37 and 5 different cubic sizes of 50, …

Verifying The Calcium Oxychloride Threshold In Cementitious Pastes, Fatoumata Traore

Graduate Theses and Dissertations

Calcium oxychloride (CAOXY) formation is a serious deterioration mechanism known to cause joint damage in concrete pavements. CAOXY is the product of a chemical reaction between calcium chloride (CaCl2) or magnesium chloride (MgCl) deicing salts and calcium hydroxide in the cementitious matrix. Currently, the accepted CAOXY threshold at which deterioration is mitigated in cementitious paste is 15 g/100 g paste (15 oz/100 oz paste); however, this limit was developed using flexural strength testing. For this investigation, the current threshold was evaluated using compressive strength and mass change over time in paste specimens exposed to CaCl2. Fly ash is used to …

Examining The Effects Of Reducing The Cement Content Of Portland Cement Concrete Pavement, Bryan Casillas

Graduate Theses and Dissertations

Portland cement is a significant component in a concrete mixture. For concrete used in portland cement concrete pavement (PCCP), the Arkansas Department of Transportation (ARDOT) specifies a minimum cementitious material content of 564 lb/yd3 and a maximum water-cementitious material ratio of 0.45. Prior research conducted at the University of Arkansas, TRC 0603, indicated concrete mixtures used in five bridge decks throughout Arkansas achieved the required 28-day strength at seven days, and the measured compressive strength at 28 days was 30% greater than required. The use of high strength concrete in pavements throughout the state can increase cracking and consequently reduce …

A Laboratory Investigation Of Cement Based Materials With Cellulose Nanofibers, Parivash Takasi

Electronic Theses and Dissertations

Cellulose Nanofibers (CNFs) are used as additives in cement-based products to modify their properties. Recent studies about the effects of CNFs on cement paste showed inconsistent results for several different important properties, including compressive strength and free shrinkage. There is reason to believe that the unsystematic results of the compressive strengths were affected by the lack of uniform dispersion of CNFs. As a potential remedy, two different mixing methods were applied. The first method used a basic mixer, but aggregates were added to the cement paste mixture to improve the blending process. The second method utilized a high-speed shear mixer …

Effect Of Mix Parameters On Strength Of Geopolymer Mortars - Experimental Study, Abdolhossein Naghizadeh, Stephen O. Ekolu

International Conference on Durability of Concrete Structures

In this article, an investigation is reported on development of strength in South African fly ash (FA) – based geopolymer mixtures. Locally available Class F, FA from one of the coal power stations was used in the investigation. The alkali-activator used consisted of sodium silicate (SS) and sodium hydroxide (SH) mixed in varied ratios of 1.0, 1.5, 2.0, 2.5 and 3.0 SS to SH. The SS of silicate modulus = 2.5 was used but the SH concentration in the activator was varied to 10, 12, 14M NaOH. Mortars of 2.25 aggregate/binder ratio were used to prepare 50 mm cubes. In …

Compressive Strength, Free Expansion And Shrinkage Of Expansive Concrete Containing Fly Ash, Warangkana Saengsoy, Rachot Chatchawan, Somnuk Tangtermsirikul

International Conference on Durability of Concrete Structures

This study is aimed to investigate effect of fly ash on compressive strength, free expansion and shrinkage of expansive concrete. High CaO and low CaO fly ashes are used in this study. The replacement percentages of total binders by fly ash are 0 and 30% by weight. The replacements of expansive additive are 0, 20 and 30 kg/m³ of concrete. The test results revealed that the use of fly ash especially the high CaO fly ash can enhance expansion of expansive concrete at early age. The use of fly ash also reduces shrinkage at long term of the expansive …

Development Of Heavyweight Self-Compacting Concrete And Ambient-Cured Heavyweight Geopolymer Concrete Using Magnetite Aggregates, Afsaneh Valizadeh, Farhad Aslani, Zohaib Asif, Matt Roso

Research outputs 2014 to 2021

Heavyweight self-compacting concrete (HWSCC) and heavyweight geopolymer concrete (HWGC) are new types of concrete that integrate the advantages of heavyweight concrete (HWC) with self-compacting concrete (SCC) and geopolymer concrete (GC), respectively. The replacement of natural coarse aggregates with magnetite aggregates in control SCC and control GC at volume ratios of 50%, 75%, and 100% was considered in this study to obtain heavyweight concrete classifications, according to British standards, which provide proper protection from sources that emit harmful radiations in medical and nuclear industries and may also be used in many offshore structures. The main aim of this study is to …

Chemical Modification Of Crumb Rubber To Increase Its Bonding With Concrete, Mary T. Mccannon, Kendall J. Sweitzer

Williams Honors College, Honors Research Projects

The hydrophilicity of crumb rubber was increased with wet chemical modification and added to concrete to increase its adhesion with concrete, consequently the compressive strength relative to that of concrete with untreated rubber. Other modification methods were tested on crumb rubber and rubber sheets to yield an increase in hydrophilicity. Certain tests were less reliable for powder testing or tedious and time consuming and concrete materials and rubber may not be homogeneous.

For wet chemical modification, several approaches were attempted. First, crumb rubber was soaked in 5% sodium hydroxide, 5% potassium permanganate and saturated sodium bisulfite, tested for hydrophilicity using …

Investigation Of Grouted Dowel Connection For Precast Concrete Wall Construction, Douglas J. Provost-Smith

Electronic Thesis and Dissertation Repository

The grouted dowel connection is a simple and cost-effective connection used in many precast concrete structural systems. The required dowel length is currently designed as a regular bar in reinforced concrete, which underestimates the bond strength, thus resulting in excessive connection lengths. Furthermore, precast wall construction continues throughout cold weather, where in-situ heating of the grout used in the grouted dowel connections is usually conducted for short periods of time. Hence, early-age exposure to subfreezing conditions may affect the quality of the grout and subsequently the bond strength of the connection, which can compromise structural integrity.

In this thesis, full-scale …

Dynamic And Static Behavior Of Hollow-Core Frp-Concrete-Steel And Reinforced Concrete Bridge Columns Under Vehicle Collision, Omar I. Abdelkarim, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents the difference in behavior between hollow-core fiber reinforced polymer-concrete-steel (HC-FCS) columns and conventional reinforced concrete (RC) columns under vehicle collision in terms of dynamic and static forces. The HC-FCS column consisted of an outer FRP tube, an inner steel tube, and a concrete shell sandwiched between the two tubes. The steel tube was hollow inside and embedded into the concrete footing with a length of 1.5 times the tube diameter while the FRP tube stopped at the top of footing. The RC column had a solid cross-section. The study was conducted through extensive finite element impact analyses …

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 …

Factorial Design Approach In Proportioning Prestressed Self-Compacting Concrete, Wu-Jian Long, Kamal Khayat, Guillaume Lemieux, Feng Xing, Wei-Lun Wang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In order to model the effect of mixture parameters and material properties on the hardened properties of, prestressed self-compacting concrete (SCC), and also to investigate the extensions of the statistical models, a factorial design was employed to identify the relative significance of these primary parameters and their interactions in terms of the mechanical and visco-elastic properties of SCC. In addition to the 16 fractional factorial mixtures evaluated in the modeled region of -1 to +1, eight axial mixtures were prepared at extreme values of -2 and +2 with the other variables maintained at the central points. Four replicate central mixtures …

Research On Embedded Sensors For Concrete Health Monitoring Based On Ultrasonic Testing, Shifeng Huang, Mimi Li, Yuesheng Xu, Dongyu Xu, Xinchun Xie, Xin Cheng

International Conference on Durability of Concrete Structures

In this article, embedded ultrasonic sensors were prepared using 1–3-type piezoelectric composite and piezoelectric ceramic as the piezoelectric elements, respectively. The frequency bandwidth of the novel embedded ultrasonic sensors was investigated. To obtain the relationship between the receiving ultrasonic velocity and compressive strength, as well as their response signals to crack damage, the sensors were fabricated and embedded into the cement mortar before testing. The results demonstrated that the piezoelectric composite sensor had wider frequency bandwidth than the piezoelectric ceramic sensor. The compressive strength and ultrasonic velocity had a positive linear relationship, with a correlation coefficient of 0.9216. The head …

Effects Of Heat Treatment On Oil Palm Shell Coarse Aggregates For High Strength Lightweight Concrete, Hilmi Mahmud

Hilmi Mahmud

In this study, the effects of heat treatment on oil palm shell (OPS) coarse aggregates are evaluated for high strength lightweight concrete (HSLWC). OPS coarse aggregates are subjected to heat treatment at two temperature settings (60 and 150. °C) and duration of heat treatment (0.5 and 1. h). The reduction in density is found to be within the range of HSLWC when heat-treated OPS aggregates are added into the oil palm shell concrete (OPSC). The results reveal that workability of the OPSC increases with an increase in temperature and duration of heat treatment of the OPS aggregates. It is found …

Effects Of Using Silica Fume And Polycarboxylate-Type Superplasticizer On Physical Properties Of Cementitious Grout Mixtures For Semiflexible Pavement Surfacing, Hilmi Mahmud

Hilmi Mahmud

Semi-flexible pavement surfacing is a composite pavement that utilizes the porous pavement structure of the flexible bituminous pavement, which is subsequently grouted with appropriate cementitious materials. This study aims to investigate the compressive strength, flexural strength, and workability performance of cementitious grout. The grout mixtures are designed to achieve high strength and maintain flow properties in order to allow the cement slurries to infiltrate easily through unfilled compacted skeletons. A paired-sample t-test was carried out to find out whether water/cement ratio, SP percentages, and use of silica fume influence the cementitious grout performance. The findings showed that the replacement of …

Engineering Properties Of Oil Palm Shell Lightweight Concrete Containing Fly Ash, Hilmi Mahmud

Hilmi Mahmud

The effect of cement replacement with type F fly ash at 0%, 10%, 30% and 50% on some engineering properties of an oil palm shell (OPS) high strength lightweight concrete was investigated. The properties studied include workability, density, compressive strength, splitting tensile strength, flexural strength, water absorption and drying shrinkage. The effect of initial water curing periods of 2, 4 and 6. days after demoulding and air drying environment on the 28-day compressive strength was also investigated. The test results showed that even with 50% substitution of cement with fly ash, a low cost grade 30 OPS lightweight concrete can …

Oil Palm Shell Lightweight Concrete Containing High Volume Ground Granulated Blast Furnace Slag, Hilmi Mahmud

Hilmi Mahmud

With the ever-increasing industrialization and urbanization, huge amounts of natural resources are required to make concrete. Green concrete can provide a solution to reducing the negative impact of the concrete industry. This paper presents the results of experiments conducted to produce green structural lightweight concrete by using oil palm shell (OPS) as coarse aggregate, and ground granulated blast furnace slag (GGBFS) as a supplementary cementing material at 30%, 50% and 70% replacement of cement, and exposed to different curing conditions. Depending on the curing condition, test results show the possibility of producing green structural lightweight aggregate concrete with 28-day compressive …

Effect Of Magnesium Sulphate On Self-Compacting Concrete Containing Supplementary Cementitious Materials, Hilmi Mahmud

Hilmi Mahmud

The length change is negligible and can be attributed to the normal distension of concrete. On the other hand, concrete suffering from mass loss gives a good indicator about the durability of SCC. Permeability of concrete is an important factor in classifying its durability generally; concrete with low Permeability will afford better protection of the reinforcement within it than concrete with high Permeability. In this paper, the assessment of magnesium sulphate (MS) attack on concrete containing various ratios of the supplementary cementitious materials (SCM) was investigated for concrete containing FA, RHA, and GGBS with cement replacement levels of 15%, 10%, …

Hardened Properties Of Self-Compacting Concrete, Marian Sabau, Traian Onet, Ana Ioana Petean

Marian Sabau

This paper presents the properties of hardened self-compacting concrete (SCC) and compare them to those reported for normally vibrated concrete (NVC). The mechanical properties evaluated are: compressive strength, modulus of elasticity, tensile strength, creep, shrinkage and bond with reinforcement. The very wide range of materials and mixes already used for SCC produced a significant scatter of data, but clear conclusions have been obtained. The compressive strength of SCC was likely to be the same or greater than that of NVC by using the same content of cement and water. Modulus of elasticity of SCC was lower than that of NVC …

Relationships Between Compressive Strength Of Cement-Slag Mortars Under Air And Water Curing Regimes, Hilmi Mahmud

Hilmi Mahmud

In this investigation 12 mortar mixes including three groups were prepared using binder contents 380 and 500 kg/m 3. All the specimens were cured after casting and demoulding in curing regimes, i.e. at room temperature (ac) and in water (wc). The highest strength was obtained for cement-slag mortars 380-wc at later ages as 80 MPa. For all groups of mortars, there could rarely be strength loss at later ages. It was observed that in duration of 3-7 days, wc is the optimum for all groups of mortars with exception of cement mortar 500 and slag mortar 500. In duration of …

Effect Of Replacement Of Normal Weight Coarse Aggregate With Oil Palm Shell On Properties Of Concrete, Hilmi Mahmud

Hilmi Mahmud

Oil palm shell (OPS) is a waste from the agricultural sector and is available in large quantities in the tropical regions. This paper investigates the effect of the replacement of normal weight coarse aggregate by oil palm shells on the compressive strength, density, modulus of elasticity, workability and water absorption. The gradation of substitution was 0, 28, 55, 83 and 100 %. Two mixes based on high strength concrete (HSC) with binder (cement + silica fume) content of 550 and 600 kg/m 3 were used. The results show that the compressive strength, density and modulus of elasticity decrease and workability …

Lightweight Concrete Made From Crushed Oil Palm Shell: Tensile Strength And Effect Of Initial Curing On Compressive Strength, Hilmi Mahmud

Hilmi Mahmud

Oil palm shell (OPS) is a waste lightweight aggregate originating from the palm oil industry, which is approximately 50% lighter than conventional aggregate. In this study, crushed old OPS was used as coarse aggregate. Compressive strength under different curing conditions and the splitting tensile and flexural strengths were compared with those of the normal weight granite concrete. The test results showed that OPS concrete with a compressive strength in the range of 34-53 MPa has a splitting tensile strength range of 2.8-3.5 MPa and flexural strength range of 4.4-7.0 MPa. The sensitivity of compressive strength of OPS concrete in this …

Lightweight Aggregate Concrete Fiber Reinforcement - A Review, Hilmi Mahmud

Hilmi Mahmud

The higher brittleness and lower mechanical properties of lightweight aggregate concrete (LWAC) compared to normal weight concrete (NWC) at the same compressive strength has prevented it from being widely used in the construction industry despite its many advantages. Studies have shown that the use of fibers in LWAC is an appropriate solution to resolve such problems. This paper reviews the influence of the addition of fibers on the properties of different types of LWAC. These properties include the workability, compressive strength, stress-strain behavior, tensile strength, modulus of elasticity, and compressive and flexural toughness. Generally, the inclusion of fibers in LWAC, …