Analysis on Crippled Sand as a Replacement for Natural Sand in High Performance Concrete

The challenge before the construction industry is to meet the demand of the efficient and economically viable construction materials posed by the huge infrastructural needs. Many nations are observing an expeditious growth in the field of construction necessitating the utilization of natural reserves for the expansion of infrastructure. This expansion is giving a warning to available reserves of nature. The natural ingredients, fine aggregates and coarse aggregate constitute more than 70% volume of the concrete. The availability of these resources is decreasing at a very high pace. In fact due to the severe problem with the availability of natural sand, the construction industry is faced with the pressing need to consider available options to lessen the reliance on natural aggregates. Copper slag being a waste material, can be used as an option for fine aggregates. The substitution of fine aggregate from nature with waste materials from industries such as copper slag offers economic and technical dominance, which are of pronounced significance in the present scenario. This study is, based on the critical review of the development of High Performance Concrete (HPC) by replacing fine aggregate with copper slag by observing various other researches and reviews. The key intent of this paper is to closely look at the copper slag utility as an unconventional material to be used as a substitute of fine aggregate and its effect on mechanical and durability parameters of HPC.

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Optimization of High-Performance-Concrete properties containing fine recycled aggregates using mixture design modeling

Frattura ed Integrità Strutturale ◽

10.3221/igf-esis.57.05 ◽

2021 ◽

Vol 15 (57) ◽

pp. 50-62

Author(s):

Tounsia Boudina ◽

Dalila Benamara ◽

Rebih Zaitri

Keyword(s):

High Performance ◽

High Performance Concrete ◽

Pozzolanic Reaction ◽

Recycled Concrete ◽

Recycled Aggregates ◽

Cement Matrix ◽

Hardened Concrete ◽

Natural Sand ◽

Fine Aggregates ◽

Result Show

This investigation means to predict and modeling the fresh and hardened concrete behavior containing fine aggregates from concrete and brick wastes, for different recycled aggregates substitution rates. To succeed this, the design of experiments DOE method was used. It is observed that slump of recycled concrete is significantly influenced by the content in recycled concrete aggregates (RCA), natural sand (NS) and recycled brick aggregates (RBA), respectively.The compressive strength (CS) reaches a maximum value of 83.48 MPa with factors values of 25% RBA, and 75% RCA. And HPC’s based on RBA sand presented greater values of flexural strength at 7 days than HPC’s based on RCA sand, it was revealed that this is due to the RBA fines pozzolanic reaction and the production of new CSHs, which leads to better cement matrix densification.Under optimal conditions, themaximum desirability is 0.65, who has given HPC no added natural sand, by mixing recycled sands RBA (9.5%) with RCA (90.5%).The statistical terms result show that the expected models are very well correlated with the experimental data and have shown good accuracy.

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Internal Curing in High Performance Concrete: Effect of Lightweight Aggregate on Shrinkage and Salt Frost Durability

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.629-630.201 ◽

2014 ◽

Vol 629-630 ◽

pp. 201-206

Author(s):

Zhi Chao Liu ◽

Will Hansen

Keyword(s):

High Performance ◽

High Performance Concrete ◽

Autogenous Shrinkage ◽

Lightweight Aggregate ◽

Cementitious Materials ◽

Supplementary Cementitious Materials ◽

Fine Aggregate ◽

Replacement Level ◽

Natural Sand ◽

Frost Durability

High performance concrete (HPC) consisting of low water-binder (w/b) ratio and supplementary cementitious materials (SCM) is more prone to shrinkage cracking if subjected to external deformation restraint. The effectiveness of using lightweight fine aggregate (LWA) for autogenous shrinkage reduction is being studied along with implications on salt frost durability. HPC consisting of 0.33 w/b ratio and cementitious replacement level up to 50% by slag cement and natural sand replacement level by LWA of up to 50% is investigated. Results indicate that these concretes exhibit excellent salt frost resistance provided the HPC is sufficiently air entrained. The mitigation of autogenous shrinkage by LWA is analyzed by comparing the spacing of LWA particles in cement paste and the flow distance of retained moisture in LWA to the adjacent paste.

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