Physical Sciences and Mathematics Commons^™

A Simple And Practical Tool For Indirect Determination Of The Unconfined Compressive Strength Of Most Common Construction Materials, Kamil Kayabali, Turgay Beyaz, İlknur Karaaslan Özdemi̇r, Deniz Yilmaz

Bulletin of the Mineral Research and Exploration

Determination of the unconfined compressive strength (UCS) of construction materials in the laboratory is tedious and time-consuming. There have been many attempts to indirectly predict UCS using simpler tools and techniques. One of them is the nail gun. The scope of this investigation is to design a nailer which can be applied all construction materials whose UCS range from 1-100 MPa. In the research, rocks, bricks, and concretes prepared in different cement/sand ratios with different strength ranges were used as materials. The unconfined compressive strength of the materials used in the experiments was first determined by conventional compression tests. The …

Preparation And Characteristics Of Inorganic Curing Foam With Large-Volume Fly Ash In Goaf, Ma Li, Du Su, Zhang Zhaoyun, Wang Hui, Zhao Liang, Zhang Bo

Coal Geology & Exploration

Air leakage in the goaf of coal mine is an important cause of coal fire disaster. The traditional filling and plugging materials are easy to crack, with poor fluidity and high cost. Therefore, it is necessary to develop new materials for effective filling and plugging of the air leakage channels. Herein, the new filling and plugging material of inorganic curing foam with large-volume fly ash was developed by optimizing the mix ratio based on material fluidity, initial setting time and compressive strength using the single factor variable method. Meanwhile, the material hydration process was characterized by the infrared spectroscopy, X-ray …

Microstructural Characterizations And Strength Development Of Self-Compacting Concrete Using Rice Husk Ash, Floyd Rey P. Plando, Joel T. Maquiling

Physics Faculty Publications

The conversion of waste and by-products into green building materials is gaining attention for a sustainable economy. Particularly, rice husk ash (RHA) is used as a precursor in self-compacting concrete due to its high pozzolanic activity. It also minimizes the use of conventional OPC as a primary binder during construction by exploiting its chemical features and characteristics as an alternative binding agent. Developing and mass-producing RHA as a cementitious material would lessen the carbon footprint that harms the environment. This study presents the compressive strength and microstructural characterizations of rice husk ash-based self-compacting concrete (RHA-SCC). The scanning electron microscope was …

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 …

Mechanical Characteristics Of Cement Paste In The Presence Of Carbon Nanotubes And Silica Oxide Nanoparticles: An Experimental Study, Moses Karakouzian, Visar Farhangi, Marzieh Ramezani Farani, Alireza Joshaghani, Mehdi Zadehmohamad, Mohammad Ahmadzadeh

Civil and Environmental Engineering and Construction Faculty Research

Considering the remarkable characteristics of nanomaterials, previous research studies investigated the effects of incorporating different types of these materials on improving the concrete properties. However, further studies are required to evaluate the complementary hybridization and synergistic influence of nanomaterials. In this research, the combined effect of adding nano silica particles (NS) and multi-walled carbon nanotubes (MWCNT) on enhancing both the compressive and flexural strengths of the cement paste was investigated. Moreover, the morphology of the interface between cement paste and aggregates was studied by scanning electron microscopy (SEM). The mixtures were prepared using three different portions of MWCNT and NS. …

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 …

Usability Of Pc-Ash As Lightweight Aggregate In Foam Concrete, Metin Davraz, Şemsettin Kilinçarslan

Bulletin of the Mineral Research and Exploration

Foam concretes can be produced with aggregate or without aggregate. In this study, the possibility of using PC ash as lightweight aggregate in the production of foam concrete was investigated. Waste- PC ash is emerging from the pulverized coal furnace about 10 tons/day in a textile factory located in the vicinity of Dinar (Afyonkarahisar). The chemical properties, particle size distribution and grain densities of PC-ash were determined. Foam concrete with a dry density of 450 kg/m3 at a cement dosage of 250 kg/m3 and w/c:0.65 was produced after the aggregate analysis. The PC-ash which is used in foam concrete mix …

Properties Of Concrete Modified With Ultra-Fine Slag, Panga Narasimha Reddy, Javed Ahmed Naqash

Karbala International Journal of Modern Science

The supplementary cementitious materials (SCM) can be used as a replacement of cement in the construction industry to minimize the drawbacks of normal concrete such as the emission of carbon dioxide so as to be eco-friendly. This paper presents the effect of ultra-fine slag (i.e. 25% of alccofine) as a replacement of cement for different water to binder ratios (i.e. 0.38, 0.4 and 0.45). The effect of alccofine on the concrete strength properties were studied at 7 and 28 days wherein considerable strength enhancement was observed compared to normal concrete. Thermogravimetric analysis was also carried out in which mass loss …

Curvature-Induced Stiffness And The Spatial Variation Of Wavelength In Wrinkled Sheets, Joseph Paulsen, Evan Hohlfeld, Hunter King, Jiangshui Huang, Zhanglong Qiu, Thomas P. Russell, Narayanan Menon, Dominic Vella, Benny Davidovitch

Physics - All Scholarship

Wrinkle patterns in compressed thin sheets are ubiquitous in nature and technology, from the furrows on our foreheads to crinkly plant leaves, from ripples on plastic-wrapped objects to the protein film on milk. The current understanding of an elementary descriptor of wrinkles—their wavelength—is restricted to deformations that are parallel, spatially uniform, and nearly planar. However, most naturally occurring wrinkles do not satisfy these stipulations. Here we present a scheme that quantitatively explains the wrinkle wavelength beyond such idealized situations. We propose a local law that incorporates both mechanical and geometrical effects on the spatial variation of wrinkle wavelength. Our experiments …

Study Of Mechanical Properties Of Pva Fiber-Reinforced Concrete With Raman Spectroscopic Analysis, Ramyasree Annam

Masters Theses & Specialist Projects

The brittleness of concrete has always been a safety and economic issue of great concern. The low tensile strength of concrete is the cause of its intrinsic brittle nature. This is critical considering the amount of concrete used for the construction of highways, buildings, and other facilities. The mechanical properties of concrete must be improved to provide upgraded construction. Crack resistant and durable concrete has always been a major goal for engineers. Many approaches have been tried to make concrete a better construction material. Fiber reinforcement is an approach which has been shown to improve the quality and durability of …

A Geomechanical Study Of The Mississippian Boone Formation, Karen Nicole Mason Buckland

Graduate Theses and Dissertations

The Boone Formation in northwest Arkansas is a chert-limestone sequence analogous to the subsurface Mississippi Lime reservoir in parts of Oklahoma and Kansas. It has low permeability and produces via horizontal drilling and hydraulic fracturing. The response to stimulation by fracturing is dependent on the quantity of chert in the area. Chert nodules and laterally extensive chert layers in the sequence are variable. Locally, cm- to dm-scale chert bedding is continuous and comprises up to 50% of the outcrop. Elsewhere, the chert is nodular and intermittent.

Samples collected from representative outcrops spanning the thickness and aerial extent of the formation …

Brittle Compressive Failure Of Salt-Water Columnar Ice Under Biaxial Loading, T. R. Smith, E. M. Schulson

Dartmouth Scholarship

The brittle failure of saline columnar ice was investigated under biaxial compression at and −10° and −40°C over the range 0 ≤ R A < 1 where R A is the ratio of the intermediate to major principal compressive stress. The major principal stress and the intermediate (confining) stress were orthogonal to the columnar axes (type-A confinement); both stresses and the c-axes of the grains were co-planar. The results confirm earlier work by Hausier (1981) and Timco and Frederking (1983, 1986) on saline ice and follow similar behavior to fresh-water columnar ice found by Smith and Schulson (1993) and Frederking (1977). Failure stress and failure mode are sensitive to the confinement and two regimes of behavior are found: the failure stress first rapidly increases with R A in the range 0 ≤ R A < R T and then tends to decrease for R A > R t. The transition stress ratio, R t changes from ≈0.2 at −10°C to ≈0.1 at −40°C. The failure mode changes from axial splitting to shear faulting in the loading plane for 0 < R A < R t. Above R t failure changes to a combined mode of splitting across the columns and shear faulting out of the loading plane. The failure-stress envelope is of a truncated Coulomb-type. Damage studies show wing cracks and local fragmentation of grains involving the brine pockets. The results are explained in terms of Coulombic sliding and Hertzian crack mechanics.