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Repeated-Load Performance of Concrete Produced with Locally Sourced Aggregates for Road and Drainage Structures
Subject area: Science,Engineering and Technology · Area of research: Concrete Materials Engineering
Abstract
Concrete for Nigerian road and drainage structures is produced from whatever coarse aggregate lies within economic haulage distance, and its mechanical quality varies widely between quarries. The static consequences are documented; the fatigue consequences are not, and limited published work relates Nigerian aggregate source to fatigue performance. This research asks how much design life is at stake. We tested 180 flexural fatigue specimens on commercial crushed granite, uncrushed river gravel and artisanal crushed granite, and analyzed the results with a stress-life regression, a two-parameter Weibull description of life scatter and a secant-modulus degradation model. The consequence is large and it inverts the ranking that mean testing would give. At a design stress ratio of 0.65, river gravel costs a factor of 7.47 in mean fatigue life and 18.08 in characteristic life at five percent failure probability; artisanal granite costs 3.48 on the mean but 22.09 on the characteristic basis, the worse material for design despite the better average. Conventional acceptance testing would miss this: across three materials whose characteristic lives differ by more than a factor of twenty, an analysis of variance on 28-day compressive strength returns p=0.051. We recommend that aggregate acceptance for repeatedly loaded concrete constrain the dispersion of the supply, and that source approval be granted per quarry rather than per rock type.
Keywords
concrete fatigue, coarse aggregate variability, stress-life relationship, weibull distribution, rigid pavement, drainage structures, nigeria
How to cite this paper
@article{1722671,
author = {Oladimeji Basit Alaka, Ridwan Tiamiyu},
title = {Repeated-Load Performance of Concrete Produced with Locally Sourced Aggregates for Road and Drainage Structures},
journal = {Iconic Research And Engineering Journals},
year = {2019},
volume = {2},
number = {10},
pages = {673-691},
issn = {2456-8880},
url = {https://www.irejournals.com/formatedpaper/1722671.pdf},
abstract = {Concrete for Nigerian road and drainage structures is produced from whatever coarse aggregate lies within economic haulage distance, and its mechanical quality varies widely between quarries. The static consequences are documented; the fatigue consequences are not, and limited published work relates Nigerian aggregate source to fatigue performance. This research asks how much design life is at stake. We tested 180 flexural fatigue specimens on commercial crushed granite, uncrushed river gravel and artisanal crushed granite, and analyzed the results with a stress-life regression, a two-parameter Weibull description of life scatter and a secant-modulus degradation model. The consequence is large and it inverts the ranking that mean testing would give. At a design stress ratio of 0.65, river gravel costs a factor of 7.47 in mean fatigue life and 18.08 in characteristic life at five percent failure probability; artisanal granite costs 3.48 on the mean but 22.09 on the characteristic basis, the worse material for design despite the better average. Conventional acceptance testing would miss this: across three materials whose characteristic lives differ by more than a factor of twenty, an analysis of variance on 28-day compressive strength returns p=0.051. We recommend that aggregate acceptance for repeatedly loaded concrete constrain the dispersion of the supply, and that source approval be granted per quarry rather than per rock type.},
keywords = {concrete fatigue, coarse aggregate variability, stress-life relationship, weibull distribution, rigid pavement, drainage structures, nigeria},
month = {April},
}