The influence of solar radiation on plastic shrinkage cracking in concrete

Published on Oct 1, 2021in Cement & Concrete Composites6.257
· DOI :10.1016/J.CEMCONCOMP.2021.104182
Gerrit M. Moelich1
Estimated H-index: 1
(Stellenbosch University),
J.E. van Zyl2
Estimated H-index: 2
(Stellenbosch University)
+ 1 AuthorsRiaan Combrinck10
Estimated H-index: 10
(Stellenbosch University)
Source
Abstract
Abstract null null Plastic shrinkage cracking (PSC) in concrete is related to the amount and rate of free pore water loss due to evaporation. This study investigates the influence of solar radiation on evaporation, the concrete temperature, plastic shrinkage and cracking. Literature suggests that exposure to solar radiation can either: increase the concrete temperature and, consequently, increase the rate of tensile strength gain resulting in less severe PSC or can increase the concrete temperature, resulting in a higher amount and rate of pore water loss to produce more severe PSC. The results of this study indicate that exposure to solar radiation significantly increases the amount and rate of pore water loss as well as plastic shrinkage and severity of PSC. To study PSC, many authors have estimated the evaporation rate from wind speed, air and concrete temperature and humidity which would result in significantly underestimating the actual evaporation rate if the concrete is exposed to moderate or high solar radiation. The accuracy of several radiation-related evaporation estimation models was evaluated by comparing the models to the actual rate of evaporation from specimens placed in the sun. A more accurate model was identified to estimate the evaporation in concrete specimens when exposed to solar radiation.
📖 Papers frequently viewed together
2 Citations
10 Citations
References42
Newest
#1Gerrit M. Moelich (Stellenbosch University)H-Index: 1
#2Jacques Kruger (Stellenbosch University)H-Index: 8
Last. Riaan Combrinck (Stellenbosch University)H-Index: 10
view all 3 authors...
Abstract In concrete, early age pore water evaporation results in volumetric shrinkage that, when restrained, can cause plastic shrinkage cracking (PSC). 3D printed concrete (3DPC) is vulnerable to PSC due to a lack of formwork, minimal bleeding water, low aggregate to binder ratio and high quantities of fines in the mixture. A novel experimental method was developed to determine the PSC risk, evaluating the efficacy of PSC prevention measures and understanding the behaviour of PSC in early age ...
16 CitationsSource
#1Gerrit M. Moelich (Stellenbosch University)H-Index: 1
#2Riaan Combrinck (Stellenbosch University)H-Index: 10
Abstract Placing fresh concrete in high evaporation conditions can increase the permeability and risk of plastic shrinkage cracking in concrete elements. Prevention measures can be time-consuming and expensive and are often neglected or incorrectly applied. This study proposes a data analysis method to identify the best time for concrete placement, most effective active curing measures, limits on weather condition for concrete placement and adequate testing conditions from location-specific weat...
6 CitationsSource
#1Riaan Combrinck (Stellenbosch University)H-Index: 10
#2William P. Boshoff (Stellenbosch University)H-Index: 16
Abstract The cracking of plastic concrete remains a problem in the construction industry due to its complexity and incomplete understanding. One of the reasons for this is the lack of knowledge regarding the tensile material properties of the plastic concrete. This paper describes and builds the appropriate test setup needed for the challenging tensile testing of plastic concrete as well as discusses the measured tensile properties. The tensile strength and Young's modulus increase exponentially...
10 CitationsSource
#1Riaan Combrinck (Stellenbosch University)H-Index: 10
#2Lourens Steyl (Stellenbosch University)H-Index: 2
Last. William P. Boshoff (Stellenbosch University)H-Index: 16
view all 3 authors...
Abstract The plastic period in conventional concrete is dominated by two volume changes namely, plastic settlement and plastic shrinkage, which if restrained can result in cracking. Although both volume changes and the resulting cracking have been well documented cracking during the plastic period remains a problem. One reason is the complex interaction between these cracks. This paper shows the necessity of considering the combined effect of plastic settlement and plastic shrinkage cracking whe...
31 CitationsSource
#1Sadegh Ghourchian (ETH Zurich)H-Index: 9
#2Mateusz Wyrzykowski (Empa: Swiss Federal Laboratories for Materials Science and Technology)H-Index: 25
Last. Pietro Lura (ETH Zurich)H-Index: 52
view all 4 authors...
Abstract The occurrence of plastic shrinkage cracking in fresh concrete may significantly compromise its service life. Therefore, it is essential to reduce the crack width with appropriate, efficient and effective methods. This study is dedicated to comparing the ability of passive mitigation methods including: Shrinkage Reducing Admixtures (SRA), accelerators based on Calcium Silicate Hydrate seeding agents and curing compounds, in controlling the plastic shrinkage cracking in the drying state....
12 CitationsSource
#1Riaan Combrinck (Stellenbosch University)H-Index: 10
#2Lourens Steyl (Stellenbosch University)H-Index: 2
Last. William P. Boshoff (Stellenbosch University)H-Index: 16
view all 3 authors...
Abstract Settlement and shrinkage cracking occurs in plastic concrete once cast up to around the final setting time. This paper reports on the influence of element depth and surface finishing operations on the cracking of plastic concrete. Deeper concrete elements are shown to have less severe shrinkage cracking when no settlement cracking is present, while when combined with settlement cracking at similar cover depths the cracking is more severe in deeper concrete. Surface finishing operations ...
13 CitationsSource
#1Filippo Giadrossich (University of Sassari)H-Index: 13
#2Marcello Niedda (University of Sassari)H-Index: 14
Last. Mario Pirastru (University of Sassari)H-Index: 13
view all 4 authors...
In Mediterranean environments, evaporation is a key component of lake water budgets. This applies to Lake Baratz in Sardinia, Italy, a closed lake that almost dried up in 2008 after a succession of years with low seasonal rainfall. We used the energy budget method and Penman's equation to estimate evaporation over Lake Baratz. We measured, using a raft station, water temperature at the surface, at 1, 2, 4, 6 m depth and at the bottom of the lake, as well as air temperature, relative humidity, wi...
18 CitationsSource
#1William P. Boshoff (Stellenbosch University)H-Index: 16
#2Riaan Combrinck (Stellenbosch University)H-Index: 10
Abstract Plastic shrinkage cracking (PShC) is one of the earliest forms of cracking in concrete as it occurs within the first few hours after the concrete has been cast. Concrete elements with large exposed surfaces are especially vulnerable to PShC. Many researchers have proposed models to simulate plastic shrinkage, bleeding and to predict the occurrence of PShC. In this paper a model to predict the degree of PShC is proposed. This model, the so called PShC Severity Model, is based on the volu...
41 CitationsSource
#1Michael ThomasH-Index: 1
52 CitationsSource
#1Mehdi Bakhshi (AECOM)H-Index: 9
#2Barzin MobasherH-Index: 55
Last. Mansour Zenouzi (Wentworth Institute of Technology)H-Index: 3
view all 3 authors...
AbstractEarly-age cracking affects the structural integrity of concrete structures and, if not inhibited, would lead to a reduction in service life. Plastic cracks are observed in the first few hours after placing the concrete, a time period well within the initial stages when the drying process is controlled by the rate of evaporation of concrete surfaces, which is roughly constant and similar to the rate of evaporation from water surfaces. In the absence of a theoretical method, this rate is c...
14 CitationsSource
Cited By1
Newest
#1Gerrit M. Moelich (Stellenbosch University)H-Index: 1
#2Jacques Kruger (Stellenbosch University)H-Index: 8
Last. Riaan Combrinck (Stellenbosch University)H-Index: 10
view all 3 authors...
Abstract null null Providing additional water to the hydrating cementitious particles is essential to achieve the optimal mechanical performance of the low w/b concrete mixes preferred for 3D printing. This study incorporates superabsorbent polymers (SAP) and additional water in 3D printed concrete (3DPC) to promote the hydration process through delayed internal water release. The study shows that a retentive SAP modifies the rheological development by absorbing the pore fluid for a short period...
1 CitationsSource