retak

Retak is a term used in Malay and Indonesian to denote a crack or fracture in a solid. In these languages, it can function as a noun describing a break, or as a verb meaning to crack. The concept is widely applied across disciplines to indicate a separation, fissure, or splitting that can affect the integrity and appearance of materials or surfaces.

In construction, engineering, and materials science, retak refers to cracks that develop in concrete, masonry, glass, ceramics, wood, or composites. Causes include mechanical stress, thermal expansion or contraction, shrinkage during drying or curing, moisture changes, and impact. Cracks can propagate under continued loading or environmental cycling, potentially reducing strength or enabling further deterioration. Prevention focuses on proper design to reduce stress concentrations, appropriate curing and moisture control, and protective measures against cycles of heating and cooling. Repair approaches range from sealing small surface cracks to injecting epoxies or other fillers for deeper or structural cracks, and applying surface coatings to limit moisture ingress.

In geology, retak describes fissures or joints in rocks that form under tectonic or thermal stress. These features influence rock permeability, stability, and erosion patterns and are considered in fields such as hydrogeology and geotechnical engineering.

In art and ceramics, retak can refer to craquelure—the network of fine cracks in painted surfaces or glazes, often resulting from aging, climate variation, or deliberate aesthetic effects.

Detection methods include visual inspection, dye penetration, ultrasonic testing, and acoustic emission monitoring.