Effect of fillers on the behaviour of heavy-weight concrete made by iron sand

Crumb rubber (CR) concrete (CRC) characterized with high ductility and environment friendliness, has recently been studied widely in the field of green concrete. Generally, high volume fraction of CR in cementitious system leads to low strength. However, the effect of CR particle size has not been concluded yet. This paper focuses on the impact of CR size on the mechanical and microstructure properties of CRC. Two novel substitution approaches of CR for natural fine aggregate are adopted. In total, 10 groups are designed and experimentally tested for their workability in fresh state and mechanical properties in hardened state. Brittleness coefficient, fineness modulus, and micro‐morphology of CRC were analyzed and discussed. Results show that as size of CR decreases, workability improves significantly, apparent density and strength exhibit a firstly decrease and then increase trend, with the lowest value obtained around 1.18 mm CR size. The brittleness of concrete was significantly improved in the presence of CR, and the improvement was more significant for smaller‐sized CR. Weak ITZs between CR particles and interfacial porosity are the main reasons for the sharp strength deterioration. Crack arresting effect of CR makes the crack propagation path more tortuous, and smaller particle‐sized CR exhibits greater capability.

Section: Fineness Modulus Of Combined Fine Aggregatementioning

confidence: 99%

Impact of crumb rubber particle size on the mechanical and microstructure properties of rubberized concrete

Ren

Tian

et al. 2022

“…It should be noted that according to past research, the use of cement substitutes and fillers in concrete including steel slag aggregates, improves flowability. [32][33][34] Therefore, in this research, the use of microsilica, in addition to improving the mechanical characteristics of HSC made with steel slag aggregates, also improves its flowability.…”

Section: Materials and MIX Designsmentioning

confidence: 99%

A high‐strength concrete resistant to elevated temperatures using steel slag aggregates

Hajiaghamemar

Mostofinejad

Bahmani

2022

“…The increasing need to produce shielding concrete required the researchers to develop new types with superior properties. Accordingly, several researchers have contributed to the development of other types of HWC, including heavyweight high‐strength concrete (HWHSC) 28 . HSC is increasingly used in concrete structures, including hospitals, industrial and military facilities, high‐rise buildings, and bridges that require high strength and durability.…”

Section: Introductionmentioning

confidence: 99%

“…Accordingly, several researchers have contributed to the development of other types of HWC, including heavyweight high-strength concrete (HWHSC). 28 HSC is increasingly used in concrete structures, including hospitals, industrial and military facilities, high-rise buildings, and bridges that require high strength and durability. According to the guidelines in ACI 211.…”

mentioning

confidence: 99%

Effects of nano titanium and nano silica on high‐strength concrete properties incorporating heavyweight aggregate

Abu el‐Hassan,

Hakeem,

Amin

et al. 2023

This investigation aims to study the effect of replacing 100% of fine and coarse aggregates with heavyweight aggregates and adding nano titanium (NT) and nano silica (NS) on shielding against radiation and on the mechanical and transport properties of heavyweight high‐strength concrete (HWHSC). In this study, 20 mixes were prepared that included the use of hematite and steel slag (SS) aggregate with NS or NT used as additions to mixes by the ratio 1% and 3% from cement weight. To study the effect of the total replacement of aggregates and the addition of nanomaterials (NMs) on the properties of HWHSC, to study engineering properties the slump, compressive strength, splitting tensile strength, flexural strength, and modulus of elasticity were applied. Density, chloride permeability, sorptivity coefficient, water permeability, and microstructure tests were also performed. To study the efficiency of shielding against radiation, linear attenuation coefficient, mass attenuation coefficient, mean‐free path, half‐value layer, and tenth‐value layer of different gamma‐ray sources of radiation 137Cs 662 (keV) and 60Co 1332 (keV) were applied. The results showed that the 100% SS and hematite replacement as coarse and fine aggregates with 3% (NS or NT) achieved the best mechanical and transport properties compared to other mixtures. While the highest density of the string containing hematite and SS was achieved with 3% of NT, with a density of 3384 kg/m3. The highest compressive strength of more than 116 MPa was achieved for the included mixture of 3% NS. The highest attenuation of gamma‐ray radiation was achieved with the application of hematite and SS aggregates with 3% of NT.