Shear friction response of lightweight concrete using bottom ash aggregates and air foams

Abstract The objective of this study is to assess the shear friction characteristics of lightweight aggregate concrete (LWAC) prepared using artificially expanded bottom ash and dredged soil granules. A total of 37 concrete mixtures were prepared under the classification of three series. In the first and second series, the natural sand content for replacing lightweight fine aggregates and the water-to-cement ratio varied to obtain different densities and compressive strengths of concrete. The third series was designed to estimate the effect of the maximum aggregate size on the friction resistance along the shear crack plane of the monolithic interfaces. The frictional angle of the LWAC tested was formulated as a function of the ratio of the effective tensile and compressive strengths of concrete through the expansion of the integrated mathematical models proposed by Kwon et al., based on the upper-bound theorem of concrete plasticity. When predicting the shear friction strength of LWAC, the present mathematical model exhibits relatively good accuracy, yielding the mean and standard deviation of the ratios between experiments and predictions of 1.06 and 0.14, respectively, whereas the empirical equations proposed by the AASHTO provision and Mattock underestimated the results. Ultimately, an advanced modification factor for shear design of LWAC is proposed as a function of the density and compressive strength of concrete and the maximum size of aggregates.

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Evaluation of Flexural and Shear Behaviors of Lightweight Concrete Eco-Thermal Panel with Bottom Ash Aggregate and Air Foam

Journal of the Korea Concrete Institute ◽

10.4334/jkci.2021.33.3.245 ◽

2021 ◽

Vol 33 (3) ◽

pp. 245-251

Author(s):

Keun-Hyeok Yang ◽

Ju-Hyun Mun

Keyword(s):

Lightweight Concrete ◽

Bottom Ash ◽

Shear Behaviors

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MINERALOGY AND ORGANIC MATTER CONTENT OF BOTTOM ASH SAMPLES FROM AGIOS DIMITRIOS POWER PLANT, GREECE

Bulletin of the Geological Society of Greece ◽

10.12681/bgsg.16673 ◽

2004 ◽

Vol 36 (1) ◽

pp. 320 ◽

Cited By ~ 5

Author(s):

N. Kantiranis ◽

Α. Georgakopoulos ◽

A. Fiiippidis ◽

A. Drakoulis

Keyword(s):

Organic Matter ◽

Power Plant ◽

Lightweight Concrete ◽

Inorganic Compounds ◽

Amorphous Material ◽

Bottom Ash ◽

Organic Matter Content ◽

Mineralogical Composition ◽

Matter Content ◽

Loss On Ignition

Four bottom ash samples from the Power Units of the Agios Dimitrios Power Plant were studied by the method of PXRD to determine their semi-quantitative mineralogical composition. Their organic matter content was calculated by a wet chemical process. Also, the loss on ignition was measured. The samples are constituted mainly of calcite, quartz and feldspars, while micas, clays, gehlenite and portlandite were determined in a few samples in smaller quantities. The amorphous material varied between 10-43 wt. %, while organic matter varied between 5-42 wt. %. Measurements of the loss on ignition overestimate the unburned lignite contents in the bottom ash samples. The management of bottom ashes with high contents of unburned lignite should differ to that of the fly ashes. The oxidation of the inorganic compounds of the unburned lignite may lead to environmental degradation of the landfill areas. Samples showing lower values of organic matter are suitable for a series of uses, such as: snow and ice control, as an aggregate in lightweight concrete masonry units,as a raw feed material for portland cement, as an aggregate in cold mix emulsified asphalt mixes, base or sub-base courses, or in shoulder construction. Systematic study of the unburned lignite of bottom ashes is needed for possible re-combustion.

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