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.

混凝土中的塑性收缩开裂 (PSC) 与蒸发造成的自由孔隙水损失的量和速率有关。本研究调查了太阳辐射对蒸发、混凝土温度、塑性收缩和开裂的影响。文献表明，暴露在太阳辐射下可以： 增加混凝土温度，从而增加抗拉强度增加率，导致 PSC 不那么严重，或者可以增加混凝土温度，导致更高的孔隙水流失量和速率，从而产生更严重的 PSC。这项研究的结果表明，暴露在太阳辐射下会显着增加孔隙水流失的数量和速度，以及 PSC 的塑性收缩和严重程度。为了研究 PSC，许多作者根据风速估计蒸发率，如果混凝土暴露在中度或高度的太阳辐射下，空气和混凝土的温度和湿度将导致显着低估实际蒸发率。通过将模型与放置在阳光下的样本的实际蒸发率进行比较，评估了几个与辐射相关的蒸发估计模型的准确性。确定了一个更准确的模型来估计混凝土试件暴露于太阳辐射时的蒸发。