Experimental Investigation of Strength of Concrete with Verbascum Thapsus (Mahur) Herbal Additive

Due to the high usage of concrete in construction, civil engineers try to decrease the defects of concrete and increase the benefits of it by using some methods. One of these methods is adding additive materials in order to achieve mentioned target. Undoubtedly in the usage of these materials engineers should pay attention to economic issues, decreasing costs of project and their availability. Most of these additive materials used in concrete, are chemicals and albeit they improve some properties of concrete they have some negative effects on other features of it. In this investigation an herbal additive material is used in concrete, this herbal material is the powder of the leaves of a plant named Mahur or Khargushak)Verbascum Thapsus) that grows in the mountains naturally. The experimental results of specimens in this investigation indicate that adding this herbal material during concrete mixing increases compressive strength up to 12% and tensile strength 20% to 25%. Due to the significant increase in tensile strength of concrete by adding the powder of Mahur additive, the surficial cracks of concrete decrease. By the way the amount of used cement in order to reach to a specific strength decreases.