EFFECT OF HEMP FIBER PRE-TREATMENT ON REPAIR CEMENT MORTAR MECHANICAL PROPERTIES

In recent years, the construction industry has seen a significant rise in the usage of natural fibers such as hemp fiber (Cannabis sativa L.) for composite materials reinforcement. The objective of the research presented in this paper was to examine the impact of the hemp fiber pre-treatment (saturated with Ca(OH)2 solution or 1.6 M NaOH solution) and condition (untreated or saturated with deionized water) on the mechanical properties of the fiber-reinforced repair cement mortar. The total of five mortar mixtures, reference one and four mixtures containing 1% hemp fibers (cut to length of the 10 mm) by mass of the cement were prepared, and their 7-day and 28-day compressive and flexural strengths were determined. The effectiveness of the applied hemp fiber pre-treatment or condition was evaluated primarily from the aspect of the mechanical properties of the examined mortars. Furthermore, based on the 28-day compressive strength results, the examined mortars were classified into one of the four classes of repair cement mortars in accordance with the standard SRPS EN 1504-3.