An experimental study investigating the impact of delayed casting on the slump behavior and compressive strength of grade 30 concrete after re-dosing with high-range superplasticizer

Concrete is ideally placed immediately after mixing, but delays are common in the ready-mixed concrete industry due to factors like long transportation distances, traffic congestion, and placement delays. These delays often cause the concrete to stiffen by the time it arrives at the site, leading...

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Main Author: Soo, Hui Wen
Format: Final Year Project / Dissertation / Thesis
Published: 2024
Subjects:
Online Access:http://eprints.utar.edu.my/7069/
http://eprints.utar.edu.my/7069/1/2004602_FYP_Report%2D_HUI_WEN_SOO.pdf
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author Soo, Hui Wen
author_facet Soo, Hui Wen
author_sort Soo, Hui Wen
building UTAR Institutional Repository
collection Online Access
description Concrete is ideally placed immediately after mixing, but delays are common in the ready-mixed concrete industry due to factors like long transportation distances, traffic congestion, and placement delays. These delays often cause the concrete to stiffen by the time it arrives at the site, leading to a significant reduction in workability, which can make placement difficult and negatively impact the concrete's strength. To address this, superplasticizers can be used to restore the concrete's plasticity, or, as a common approach, extra water is sometimes added to the mixture before discharge. This study aims to examine the effects of casting delays (slump reduction from 100mm to 50mm) on the slump behaviour and compressive strength of grade 30 concrete. It also explores the effects of retempering with water and the impact of re-dosing with varying dosages of the high-range superplasticizer, MasterGlenium ACE 8538, in dosages from 0.05% to 0.30% at 0.05% intervals. Workability tests revealed that a 0.1% dosage of high-range superplasticizer was sufficient to restore the workability of the control mix, while a 0.15% dosage achieved the highest workability before segregation occurred. It was also found that although retempering with water can improve workability, it may significantly reduce compressive strength. In contrast, re-dosing with an appropriate amount of superplasticizer improves both workability and compressive strength, making it the more favorable retempering method. This study also identified the optimal dosage as 0.1% for regaining slump and 0.15% for achieving the best balance of workability and strength.
first_indexed 2025-11-15T19:44:53Z
format Final Year Project / Dissertation / Thesis
id utar-7069
institution Universiti Tunku Abdul Rahman
institution_category Local University
last_indexed 2025-11-15T19:44:53Z
publishDate 2024
recordtype eprints
repository_type Digital Repository
spelling utar-70692025-01-19T02:07:38Z An experimental study investigating the impact of delayed casting on the slump behavior and compressive strength of grade 30 concrete after re-dosing with high-range superplasticizer Soo, Hui Wen TA Engineering (General). Civil engineering (General) TC Hydraulic engineering. Ocean engineering Concrete is ideally placed immediately after mixing, but delays are common in the ready-mixed concrete industry due to factors like long transportation distances, traffic congestion, and placement delays. These delays often cause the concrete to stiffen by the time it arrives at the site, leading to a significant reduction in workability, which can make placement difficult and negatively impact the concrete's strength. To address this, superplasticizers can be used to restore the concrete's plasticity, or, as a common approach, extra water is sometimes added to the mixture before discharge. This study aims to examine the effects of casting delays (slump reduction from 100mm to 50mm) on the slump behaviour and compressive strength of grade 30 concrete. It also explores the effects of retempering with water and the impact of re-dosing with varying dosages of the high-range superplasticizer, MasterGlenium ACE 8538, in dosages from 0.05% to 0.30% at 0.05% intervals. Workability tests revealed that a 0.1% dosage of high-range superplasticizer was sufficient to restore the workability of the control mix, while a 0.15% dosage achieved the highest workability before segregation occurred. It was also found that although retempering with water can improve workability, it may significantly reduce compressive strength. In contrast, re-dosing with an appropriate amount of superplasticizer improves both workability and compressive strength, making it the more favorable retempering method. This study also identified the optimal dosage as 0.1% for regaining slump and 0.15% for achieving the best balance of workability and strength. 2024 Final Year Project / Dissertation / Thesis NonPeerReviewed application/pdf http://eprints.utar.edu.my/7069/1/2004602_FYP_Report%2D_HUI_WEN_SOO.pdf Soo, Hui Wen (2024) An experimental study investigating the impact of delayed casting on the slump behavior and compressive strength of grade 30 concrete after re-dosing with high-range superplasticizer. Final Year Project, UTAR. http://eprints.utar.edu.my/7069/
spellingShingle TA Engineering (General). Civil engineering (General)
TC Hydraulic engineering. Ocean engineering
Soo, Hui Wen
An experimental study investigating the impact of delayed casting on the slump behavior and compressive strength of grade 30 concrete after re-dosing with high-range superplasticizer
title An experimental study investigating the impact of delayed casting on the slump behavior and compressive strength of grade 30 concrete after re-dosing with high-range superplasticizer
title_full An experimental study investigating the impact of delayed casting on the slump behavior and compressive strength of grade 30 concrete after re-dosing with high-range superplasticizer
title_fullStr An experimental study investigating the impact of delayed casting on the slump behavior and compressive strength of grade 30 concrete after re-dosing with high-range superplasticizer
title_full_unstemmed An experimental study investigating the impact of delayed casting on the slump behavior and compressive strength of grade 30 concrete after re-dosing with high-range superplasticizer
title_short An experimental study investigating the impact of delayed casting on the slump behavior and compressive strength of grade 30 concrete after re-dosing with high-range superplasticizer
title_sort experimental study investigating the impact of delayed casting on the slump behavior and compressive strength of grade 30 concrete after re-dosing with high-range superplasticizer
topic TA Engineering (General). Civil engineering (General)
TC Hydraulic engineering. Ocean engineering
url http://eprints.utar.edu.my/7069/
http://eprints.utar.edu.my/7069/1/2004602_FYP_Report%2D_HUI_WEN_SOO.pdf