Civil and Environmental Engineering Commons^™

Application Of Mangrove Timber In Reinforcing Concrete, John K. Makunza Jkm

Tanzania Journal of Engineering and Technology (TJET)

Use of mangrove timber beams for supporting floor slabs in historic buildings in Zanzibar Stone Town is still applied although the available structural data on mangrove timber is inadequate. This concern has called for an investigation on the structural properties of mangrove timber, so that the information obtained could help to establish the structural strength of the existing floor slabs in historic buildings. Hence, mangrove timber specimens were sampled from Zanzibar, and tested in the laboratory for their strengths in tension, compression and shear. The test results showed that mangrove is a hardwood timber of strength class D70, the highest …

Study On Effect Of Nanomodified Additives On Properties Of Concrete Mixtures During Winter Season, Li Yulin, Liang Hongjie, Liang Junlin, Rong Hongliu, Yang Xiaolong

Journal of China & Foreign Highway

To solve the difficult placement of small structures on highways caused by the decreasing workability of cement concrete construction in winter seasons, this paper developed a nanomodified additive to investigate its effect on the performance of cement concrete. Sulfonate naphthaleneformaldehyde (SNF), nanoSiO2, rosin soap (WSR) and sodium nitrate (NaNO3) were formulated into a variety of additives in different ratios and mixing contents to prepare cement concrete, with the fluidity, segregation and compressive strength studied. The results show that the optimal ratio (mass) of nanomodified additives is SNF:0.4%, nanoSiO2:0.1%, WSR:0.05%, and NaNO3:4.0%. The fluidity, segregation and compressive strength of the concrete …

Experimental Study On Mechanical Properties Of Steel-Polypropylene Mixed Fiber Rubber Concrete, Qiu Jiandong

Journal of China & Foreign Highway

Waste rubber materials can be recycled to obtain rubber aggregates, which can be employed in cement concrete products. This paper carried out mechanical performance tests on ordinary concrete and rubber concrete (rubber substitution rate of 20%) with different fiber combinations (doped MS, co-doped PP, and mixed MS-PP), and mainly examined the slump, density, compressive strength, modulus of elasticity, split tensile strength, and rupture strength of the concrete. The results show that the relevant performance indexes decrease significantly after 20% of rubber aggregate is added to the concrete. However, the mechanical performance of ordinary concrete and rubber concrete with the combination …

Utilizing Waste Latex Paint Toward Improving The Performance Of Concrete, Mohamed Leithy, Eslam Gomaa, Ahmed A. Gheni, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this paper, incorporating the waste latex paint (WLP) into the conventional concrete as a partial replacement of sand to improve its durability was investigated. The fresh and hardened characterizations, in addition to the durability of concrete, were examined. The slump test was used to evaluate the fresh properties, while the hardened properties were evaluated through the volume of voids and absorption rate, in addition to the compressive, splitting tensile, and flexural strengths tests. The durability performance was evaluated by the surface resistivity, bulk electrical resistivity, as well as freeze and thaw resistance tests. The results showed a reduction in …

Experimental Investigation Of Water Quality Impact On The Compressive Strength Of Concrete, Shayan Sharifzad

Civil Engineering Dissertations - Archive

Water is an indispensable component in concrete, as it enables crucial chemical reactions. Therefore, the quality of water used in concrete plays a vital role in its performance. Contaminated water, sewage, or high-salt water can disrupt the cement's setting process and overall performance. As a result, it is crucial to prioritize the use of drinking water or water of equivalent quality in concrete production. While the ideal water-to-cement ratio for concrete is typically around 0.20, practical considerations often require a higher water content ranging from 0.30 to 0.70. This increased water consumption is necessary to ensure workability and achieve optimal …

Influence Of Steel Fiber And Polymer Emulsion On Mechanical Properties And Microstructure Of Concrete, Guo Guanglei, Sun Shiqiang, Li Ying, Zheng Yiwei, Mei Yingjun

Journal of China & Foreign Highway

The microstructure and mechanical properties of concrete were improved by adding steel fiber and polymer emulsion. The working properties and mechanical properties of steel fiber concrete, polymer emulsion-modified concrete, and steel fiber polymer concrete were tested at 3 d, 28 d, and 90 d. Nitrogen adsorption test, mercury injection test, and density method were used to obtain the total pore volume, median pore size, and closed porosity of concrete. The influence of steel fiber and polymer emulsion on the microstructure and mechanical properties of concrete was analyzed. The results show that the compressive strength of concrete after adding steel fiber …

Nonlinear Impact-Echo Test For Quantitative Evaluation Of Asr Damage In Concrete, Clayton Malone, Hongbin Sun, Jinying Zhu

Department of Civil and Environmental Engineering: Faculty Publications

Nonlinear acoustic methods demonstrate high sensitivity for concrete damage evaluation. Among these methods, nonlinear resonance acoustic methods have been widely used in laboratory tests on small scale test samples. In this study, a nonlinear impact-echo (IE) method was proposed for concrete damage evaluation, in which the IE frequency shift was measured at different impact force levels. The nonlinear IE test is similar to the nonlinear impact resonance acoustic spectroscopy (NIRAS) test in the experimental setup and analysis method. How- ever, the nonlinear IE test excites a local thickness resonance mode of a member instead of the global resonance vibration. Therefore, …

Accelerated Sulfate Attack Testing For Concrete, Craig Newtson, Seyedsaleh Mousavinezhad, William Toledo, Federico Aguayo

Data

Extensive research has been conducted on sulfate attack of concrete structures, however, the need to adopt use of more sustainable materials is driving a need for a quicker test method to assess sulfate resistance. Class F fly ash, which is a byproduct of coal combustion for electricity generation, has historically been used in concrete mixtures to improve sulfate resistance. However, environmental considerations and evolving energy industry has decreased its availability, requiring the identification of economically viable and environmentally friendly alternatives to fly ash. Another challenge in addressing sulfate attack durability issues in concrete is that the standard sulfate attack test …

Accelerated Sulfate Attack Testing For Concrete, Craig Newtson, Seyedsaleh Mousavinezhad, William Toledo, Federico Aguayo

Publications

Extensive research has been conducted on sulfate attack of concrete structures, however, the need to adopt use of more sustainable materials is driving a need for a quicker test method to assess sulfate resistance. Class F fly ash, which is a byproduct of coal combustion for electricity generation, has historically been used in concrete mixtures to improve sulfate resistance. However, environmental considerations and evolving energy industry has decreased its availability, requiring the identification of economically viable and environmentally friendly alternatives to fly ash. Another challenge in addressing sulfate attack durability issues in concrete is that the standard sulfate attack test …

Optimal Concrete Mix Design And Finish For Skateboarding Performance, Lohgan Christoper Spencer

Construction Management

While concrete has been used in construction for hundreds of years, the introduction of concrete to skateboarding is a relatively new development. Concrete and concrete finishes are very well studied in the context of buildings and building design. Shotcrete is also very well understood as it has been in use for over 100 years. Because it is a relatively new sector of the industry, concrete skatepark construction is an area that has plenty of room for research and development. This research paper will describe the finish methods and mix designs used for concrete skatepark construction by leading skatepark construction companies …

City Farm Slo ‘Garden For All’ – Shade Structure, Reed Aitken

Construction Management

Local non-profit, City Farm SLO, recently presented an opportunity for four Cal Poly Construction Management students to complete senior projects to construct their vision of a “Garden for All.” This paper will focus on the design, preconstruction, and construction processes necessary to complete the shade structure. The project will provide much needed shade to an outdoor classroom area where City Farm SLO hosts farm based education programs all year round. The completion of this senior project required thorough design, estimating, coordination, and construction efforts, while keeping safety and sustainable building practices at the forefront of every decision. This was particularly …

Slab Extension At Woods Humane Society, Corey K. Smith

Construction Management

Woods Humane Society is an animal shelter that provides pet rehabilitation and adoption services to San Luis Obispo and surrounding areas. The Woods’ facility contains a number of kennels for dogs as well as numerous outdoor, fenced-in, concrete exercise yards. These yards give dogs the opportunity to play outside a few times a day allowing them to get vital exercise. One of these yards on the south side of the property had an exterior fence that was offset from an existing slab on the interior of the fence by one foot. This was an issue for the shelter as dogs …

Effects Of Admixes On The Compressive Strength Of Permeable Concrete, James T. Lyon

Construction Management

Compression tests were performed on three samples of permeable concrete to evaluate the effects of admixes on a conventional permeable concrete. The first mix served as the control, representing a standard permeable concrete sample. The second mix replicated the control but added a small amount of fiberglass, accounting for 0.5% of the cement's weight. The third mix again mirrored the control and incorporated the manufacturer's recommended amount of a water reducing admix known as "Reducer 555". The objective of testing the two new mixes against the control mix was to evaluate the potential increase in ultimate compressive strength. Four 6” …

Optimization Of The Self-Healing Efficiency Of Bacterial Concrete Using Impregnation Of Three Different Precursors Into Lightweight Aggregate, Omar Omar

LSU Master's Theses

Concrete is the most broadly used construction material; thus, developing sustainable concrete is essential to decrease greenhouse gas (GHG) emissions from concrete production. Implementation of self-healing concrete technologies is a promising approach to enhance the durability and sustainability of the transportation infrastructure. Among these technologies, bacterial concrete has the potential to seal microcracks through microbial induced calcite precipitation (MICP). Bacterial protection is essential to ensure the viability of this technology due to concrete’s harsh environment. Additionally, the success of this technology depends on the presence of an adequate mineral precursor compound and nutrient for the bacteria. As such, the main …

Development Of Self-Stressing Ultra High-Performance Concrete Using Expansive Chemical Admixtures, Lane Edwards

Graduate Theses and Dissertations

This study investigated the effects of expansive chemical admixtures on ultra-high performance concrete (UHPC) and self-stressing mechanisms. A literature review was performed to determine different types of expansive admixtures for feasibility of the self-prestressing concept. Ultimately it was decided that type-k cement, made by combining Komponent admixture with conventional UHPC, was the most suitable option due to its effects on wet and hardened concrete properties. Mix designs with varying amounts of Komponent were developed to test the effects the admixture had on various properties. Tested properties included, workability, compressive strength, expansion, short-term shrinkage, long-term shrinkage, and developed prestress. The development …

On The Feasibility Of Embedding Fe-Sma Short-Fibers In Ultra-High-Performance Concrete For Self Prestressing, Gavin Briggs

Graduate Theses and Dissertations

Prestressing concrete is common practice in the construction industry. Current prestressing methods are often used for large, straight members and come with geometric limitations for curved or thin-walled members. Shape memory alloy short fibers embedded within concrete mixes may allow for the prestressing of geometries not possible with traditional methods. This study reviews past research on prestressing concrete with shape memory alloys, evaluates the achievable recovery stress within an Fe-SMA (when deformed at room temperature), and examines the mechanical behavior of Ductal dark grey UHPC when heated to 250 °C. The flexural behavior, compressive strength, and fiber-to-concrete bond strength of …

Rilem Tc 266-Mrp: Round-Robin Rheological Tests On High Performance Mortar And Concrete With Adapted Rheology—Rheometers, Mixtures And Procedures, Dimitri Feys, Mohammed Sonebi, Sofiane Amziane, Chafika Djelal, Khadija El-Cheikh, Shirin Fataei, Markus Greim, Irina Ivanova, Helena Keller, Kamal Khayat, Laurent Libessart, Viktor Mechtcherine, Ivan Navarrete, Arnaud Perrot

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Recent developments in understanding the rheology of mortar and concrete as well as applying this understanding in the practice of construction necessitate an accurate assessment of materials' rheological properties. It is well known that different rheometers for mortar and concrete deliver different results, as this was shown over 15 years ago in two measuring campaigns comparing concrete rheometers. Considering newly developed rheometers, including those to evaluate interface rheology and structural build-up at rest, as well as additional measurement procedures and data interpretation techniques, a new comparison campaign was carried out in 2018 at the Université d'Artois, in Bethune, France. This …

The Influence Of The Addition Of Recycled Asphalt Shingles On The Compressive Strength Of Concrete, William E. Webb

Honors College Theses

The purpose of this study is to explore the effect of recycled asphalt shingles (RAS) as an additive on the compressive strength of concrete. This was accomplished by designing a concrete mix and creating 4” by 8” cylindrical test specimens containing 0, 5, 10, and 15 percent RAS by weight. The compressive strength was measured through axial loading until failure utilizing a compression testing apparatus. With these results, a relationship between the content of RAS and compressive strength was able to be developed, giving insight as to how RAS could be used in concrete mixes in the future. This study …

Adiabatic Temperature Rise And Durability Performance Of Slag Blended Concrete, Hai Zhu

USF Tampa Graduate Theses and Dissertations

Performance and durability of slag blended concrete was investigated in this study focusing on slag and cement characteristics. Seven slags with variable Al2O3 content, Al2O3/MgO ratio and fineness were selected for investigation. The eight selected cements included ASTM Type I, Type I(HA), Type II(MH), Type II(MH)(HA), and Type IL(10 and 14). Cementitious materials studied here were subjected to a battery of tests including physical, chemical and mineralogical characterization. Performance and durability testing included heat of hydration measurements, sulfate optimization, external sulfate resistance, adiabatic temperature rise and chloride ingress.

Adiabatic temperature rise was assessed on 60% slag blended concrete, using Type …

Research And Analysis On Controlled Blasting Demolition Of Continuous Thin‐Walled Box Ribbed Arch Bridge, Ma Shaojun, Chen Huibin, Chai Wendong, Zhang Chunquan, Wang Yuan

Journal of China & Foreign Highway

The 1st bridge of the Jialing River in Pengan County is erected over the Jialing River, a tributary of the Yangtze River. Due to earthquakes and perennial high load operation, the overall technical condition is “Class Ⅴ”, which cannot meet the requirements of the design load grade. This bridge is the longest highway bridge dismantled in Sichuan Province. Its structure is a multi-span continuous thin-walled box ribbed arch bridge. In addition, there are obvious diseases, so the demolition is difficult, and the safety risk is great. For the demolition of the bridge by controlled blasting, numerical simulation, shaped charge cutting …

Research And Analysis On Controlled Blasting Demolition Of Continuous Thin‐Walled Box Ribbed Arch Bridge, Ma Shaojun, Chen Huibin, Chai Wendong, Zhang Chunquan, Wang Yuan

Journal of China & Foreign Highway

The 1st bridge of the Jialing River in Pengan County is erected over the Jialing River, a tributary of the Yangtze River. Due to earthquakes and perennial high load operation, the overall technical condition is “Class Ⅴ”, which cannot meet the requirements of the design load grade. This bridge is the longest highway bridge dismantled in Sichuan Province. Its structure is a multi-span continuous thin-walled box ribbed arch bridge. In addition, there are obvious diseases, so the demolition is difficult, and the safety risk is great. For the demolition of the bridge by controlled blasting, numerical simulation, shaped charge cutting …

United Methodist Children Center Drain Project, Andy Abdelnour

Construction Management

The United Methodist Children Center in San Luis Obispo is a preschool for young children in our community. Some of these students are the children of Cal Poly faculty and staff. The previous drain was not draining water properly and was uneven with bumps and dips that became a hazard for the children. Children would trip, fall, and hurt themselves on the drain. A team of two Cal Poly Construction Management students Ethan Lin and Andy Abdelnour worked together to estimate, design, coordinate, demolish, and construct a new section of the drain that would be safe for the students. The …

Editorial: Nanoscale Insight Into The Hydration Products Of Cementitious Materials: From Theory To Engineering, Huiwen Sun, Muhan Wang, Hongyan Ma, Xiao Wang, Bo Pang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.

Editorial: Ultra-High Performance Concrete: Computation And Simulation Methods, Xinpeng Wang, Yitong Ma, Dongshuai Hou, Hongyan Ma, Yue Zhang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.

Nondestructive Evaluation Of Structural Defects In Concrete Slabs, Ehsanul Kabir

College of Graduate Studies: Theses & Dissertations

Nondestructive testing (NDT) is a reliable method for determining the structural integrity of new and old construction and understanding the condition of structural defects. It is widely acknowledged that the interpretation of nondestructive evaluation (NDE) has a significant impact on the reliability and consistency of this technology. However, NDT data acquisition remains subjective and heavily dependent on the operator’s knowledge and expertise. As a result, there are still issues to be resolved regarding the imaging and diagnostic procedures for NDT-based concrete inspection. NDT methods such as ground penetrating radar (GPR), and impact-echo (IE), have been extensively used to inspect concrete …

Analytical And Numerical Behavior Of Double Composite Steel Bridges, Emad M. Hassan, Hussam Mahmoud

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Steel plate girders are considered a viable solution for the construction of medium- to long-span bridges. Despite their many advantages, various concerns have been raised regarding their maintenance due to the potential of fatigue crack initiation at welded details, accelerated corrosion in thin webs, and trapped debris around stiffeners. The use of rolled beams, on the other hand, can be very beneficial because they require much less maintenance. However, they are limited in size, which imposes constraints on their use to relatively short-span bridges due to deflection requirements. In this study, the behavior of the double composite superstructure system was …

Performance And Durability Assessment Of Concrete Bridge Deck Sealants, Bipin Adhikari

Electronic Theses and Dissertations

No abstract provided.

Feasibility Of Applying Motion Magnification In Subsurface Defect Detection For Concrete And Fiber-Reinforced Polymer Specimens, Nagavardhani Malineni

Graduate Theses, Dissertations, and Problem Reports (ETD)

Irrespective of size and complexity, every civil infrastructure needs certain scrutiny regarding its structural health to ensure its serviceability during its lifetime. In olden times such scrutiny was done with the aid of destructive testing methods using sensors that required cumbersome and expensive installations and led to the destruction of at least part of the tested specimen. However, in recent times, many non-destructive methods, such as acoustic emission testing, electromagnetic testing, and laser testing methods have emerged, leaving the specified tested specimen undisturbed. With the advancement in sensor technology like motion magnification and with the help of access to high-speed …

Concrete Technology In A Rapidly Growing Urban Environment – The Case Of Dar Es Salaam City, John K. Makunza Jkm

Tanzania Journal of Engineering and Technology (TJET)

Concrete is a building material that is used in great quantities second only to our use of water. The ingredient materials of concrete include cement, fine and coarse aggregates plus a reasonable amount of water, and sometimes additives. The construction of various structures like, residential buildings, commercial buildings, hospitals, schools, bridges, etc., needs good quality concrete. Good modern technologies are needed by the construction industry in order to effectively construct buildings which are durable. A study has been done with the main objective of assessing the concrete technologies existing in rapid growing cities in Sub-Sahara Africa like Dar es Salaam, …

Shape Deformities In Recycled Concrete As A Substitute Aggregate In Concrete, Carson D. Timmerman

Construction Management

Concrete is a universal material that is used widely across the construction industry. Within a standard concrete mix, a fine aggregate and a coarse aggregate are added to the mix design to help with solidity and compressive strength in the mixture. The admixtures, additives, slump, and mix ratios will differ based on the compressive strength you're trying to attain. This paper directly reflects the results of the differences between shapes in recycled concrete used as a coarse aggregate substitute in concrete mixes. As the construction industry grows, so does outreach towards sustainability and reusing materials anywhere the industry can. Testing …