Engineering Commons^™

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 …

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 …

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 …

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.