Applicability of ferrosilicon slag for a cementitious binder in concrete mix

A new kind of high strength cementitious material is made from phosphogypsum (PG), active carbon and fly-ash. Through the orthogonal research, it was showed that the calcination temperature, retention time, dosage of active carbon and fly ash on the compressive strength of cementitious binder are the most important. The result also showed that, in the conditions of temperature 1200°C, time retention 30 min, dosage of active carbon 10%, dosage of fly ash 5%, the compressive strength of the cementitious material for 3d and 28d could reach to 46.35MPa and 92.70MPa, the content of sulfur trioxide was 11.60% accordingly. A lot of active mineral materials, such as dicalcium silicate, tricalcium silicate, tricalcium aluminate were formed in the calcination. The C-S-H gel, calcium hydroxide and ettringite were found in 3d and 28d hydrates. It is found that the lime saturation ratio and silica modulus need to be control between 0.40~0.65 and 4~8 in order to produce high strength cementitious material.

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Functional Method of Designing Self-Compacting Concrete

Materials ◽

10.3390/ma14020267 ◽

2021 ◽

Vol 14 (2) ◽

pp. 267

Author(s):

Tomasz Rudnicki

Keyword(s):

Coarse Aggregate ◽

Cement Mortar ◽

Experimental Studies ◽

Functional Method ◽

Structural Viscosity ◽

Self Compacting Concrete ◽

Theoretical Assumptions ◽

Concrete Mix ◽

Selection Of ◽

Double Coating

The article presents a new functional method of designing self-compacting concrete (SCC). The assumptions of the functional method of designing self-compacting concrete were based on the double coating assumption (i.e., it was assumed that the grains of coarse aggregate were coated with a layer of cement mortar, whereas the grains of sand with cement paste). The proposed method is composed of four stages, each of which is responsible for the selection of a different component of the concrete mix. The proposed designing procedure takes into consideration such a selection of the mineral skeleton in terms of the volumetric saturation of the mineral skeleton, which prevents the blocking of aggregate grains, and the designed liquid phase demonstrated high structural viscosity and low yield stress. The performed experimental studies, the simulation of the elaborated mathematical model fully allowed for the verification of the theoretical assumptions that are the basis for the development of the method of designing self-compacting concrete.

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Influence of concrete mix proportions on lifetime flexural load-bearing capacity of RC beams under chloride corrosion of rebars

Structures ◽

10.1016/j.istruc.2021.01.009 ◽

2021 ◽

Vol 29 ◽

pp. 2017-2027

Author(s):

Fatemeh Asen ◽

Mehdi Dehestani

Keyword(s):

Bearing Capacity ◽

Rc Beams ◽

Load Bearing Capacity ◽

Load Bearing ◽

Chloride Corrosion ◽

Concrete Mix

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Consistency and mechanical properties of sustainable concrete blended with brick dust waste cementitious materials

SN Applied Sciences ◽

10.1007/s42452-021-04430-w ◽

2021 ◽

Vol 3 (4) ◽

Author(s):

S. Y. Amakye ◽

S. J. Abbey ◽

A. O. Olubanwo

Keyword(s):

Tensile Strength ◽

Fresh Concrete ◽

Environmental Benefits ◽

Partial Replacement ◽

Target Range ◽

Hardened Concrete ◽

Index Test ◽

Demolition Waste ◽

Concrete Mix ◽

Brick Dust

AbstractThe reuse of waste materials in civil engineering projects has become the topic for many researchers due to their economic and environmental benefits. In this study, brick dust waste (BDW) derived from cutting of masonry bricks and demolition waste which are normally dumped as land fill is used as partial replacement of cement in a concrete mix at 10%, 20% and 30% respectively, with the aim of achieving high strength in concrete using less cement due to the environmental problems associated with the cement production. To ascertain the effects of BDW on the consistency and mechanical performance of concrete mix, laboratory investigations on the workability of fresh concrete and the strength of hardened concrete were carried out. Slump and compaction index test were carried out on fresh concrete mix and unconfined compressive strength (UCS) test and tensile strength test were conducted on hardened concrete specimen after 7, 14 and 28 days of curing. The results showed high UCS and tensile strength with the addition of 10% BDW to the concrete mix, hence achieving the set target in accordance with the relevant British standards. A gradual reduction in strength was observed as BDW content increases, however, recording good workability as slump and compaction index results fell within the set target range in accordance with relevant British standards. Findings from this study concluded that BDW can partially replace cement in a concrete mix to up to 30% igniting the path to a cleaner production of novel concrete using BDW in construction work.

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Design and characterization of concrete masonry parts and structural concrete using repurposed plastics as aggregate

Journal of the Mechanical Behavior of Materials ◽

10.1515/jmbm-2019-0010 ◽

2019 ◽

Vol 28 (1) ◽

pp. 81-88

Author(s):

Miguel A. González-Montijo ◽

Hildélix Soto-Toro ◽

Cristian Rivera-Pérez ◽

Silvia Esteves-Klomsingh ◽

Oscar Marcelo Suárez

Keyword(s):

Structural Strength ◽

Construction Materials ◽

Tensile Tests ◽

Compression Tests ◽

Conventional Concrete ◽

Structural Capacity ◽

Plastic Type ◽

Concrete Mix ◽

Scientists And Engineers

AbstractHistorically known for being one of the major pollutants in the world, the construction industry, always in constant advancement and development, is currently evolving towards more environmentally friendly technologies and methods. Scientists and engineers seek to develop and implement green alternatives to conventional construction materials. One of these alternatives is to introduce an abundant, hard to recycle, material that could serve as a partial aggregate replacement in masonry bricks or even in a more conventional concrete mixture. The present work studied the use of 3 different types of repurposed plastics with different constitutions and particle size distribution. Accordingly, several brick and concrete mix designs were developed to determine the practicality of using these plastics as partial aggregate replacements. After establishing proper working material ratios for each brick and concrete mix, compression tests as well as tensile tests for the concrete mixes helped determine the structural capacity of both applications. Presented results proved that structural strength can indeed be reached in a masonry unit, using up to a 43% in volume of plastic. Furthermore, a workable structural strength for concrete can be achieved at fourteen days of curing, using up to a 50% aggregate replacement. A straightforward cost assessment for brick production was produced as well as various empirical observations and recommendations concerning the feasibility of each repurposed plastic type examined.

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