;Chemical shrinkage (self-desiccation)
The cement hydration process consumes water molecules. The sum of the volumes of the hydration products present in the hardened cement paste is smaller than the sum of the volumes of the reacting mineral phases present in the cement clinker. Therefore, the volume of the fresh and very young concrete undergoes a contraction due to the hydration reaction: it is what is called "chemical shrinkage" or "self-desiccation". It is not a problem as long as the very fresh concrete is still in a liquid, or a sufficiently plastic, state and can easily accommodate volume changes (contraction). 
;Plastic shrinkage
Later in the setting phase, when the fresh concrete becomes more viscous and starts to harden, water loss due to unwanted evaporation can cause "plastic shrinkage". This occur when concrete is placed under hot conditions, e.g. in the summer and not sufficiently protected against evaporation. Cracks often develop above reinforcement bars because the contraction of concrete is locally restrained at this level and the still setting and weakly resistant concrete cannot freely shrink.
;Cracks due to a poor curing (loss of water at early age)
The curing of concrete when it continues to harden after its initial setting and progressively develops its mechanical strength is a critical phase to avoid unwanted cracks in concrete. Depending on the temperature (summer or winter conditions) and thus on the cement hydration kinetics controlling the setting and hardening rate of concrete, curing time can require a few days only (summer) or up to two weeks (winter). It is then capital to avoid losses of water by evaporation because water is still necessary for continuing the slow cement hydration. Water loss at this stage aggravates concrete shrinkage and can cause unacceptable cracks to develop in concrete. Cracks form in case of a too short, or too poor, curing when young concrete has not yet developed a sufficient early strength to withstand tensile stress caused by undesirable and premature drying. Cracks development occurs when early-age concrete is insufficiently protected against desiccation and too much water evaporates with heat because of unfavorable meteorological conditions: e.g, high temperature, direct solar insolation, dry air, low relative humidity, and high wind speed during summer, or in hot conditions. Curing is intended to maintain moist conditions at the surface of concrete. It can be done by letting the formworks in place for a longer time, or by applying a hydrophobic thin film of an oily product (curing compound) at the concrete surface (e.g., for large slabs or rafts) to minimize water evaporation.
;Drying shrinkage
After sufficient setting and hardening of concrete (after 28 days), the progressive loss of capillary water is also responsible for the "drying shrinkage". It is a continuous and long-term process occurring later during the concrete life when under dry conditions the larger pores of concrete are no longer completely saturated by water.
;Thermal cracks
When concrete is subject to an excessive temperature increase during its setting and hardening as in massive concrete structures from where cement hydration heat cannot easily escape (semi-adiabatic conditions), the temperature gradients and the differential volume changes can also cause the formation of thermal cracks and fissures. To minimize them a slowly-setting cement (CEM III, with blast furnace slags) is preferred to a quickly setting cement (CEM I: Portland cement). Pouring concrete under colder conditions (e.g., during the night, or in the winter), or using cold water and ice mixed with cooled aggregates to prepare concrete, may also contribute to minimize thermal cracks.