The effects of waste marble dust and polypropylene fiber contents on mechanical properties of gypsum stabilized earthen Ayse Pekrioglu Balkis Cyprus International University, Haspolat, North Cyprus, via Mersin 10, Turkey highlights  Mechanical properties of fiber-added adobe.  Waste marble dust- and polypropylene-added adobe blocks.  Stabilization with polypropylene fibers proposed.  132 samples prepared for 07 and 28 day periods.  Results indicate increased compressive strength and flexural strength by using 0.5% polypropylene fibers. article info Article history: Received 18 August 2016 Received in revised form 14 November 2016 Accepted 28 December 2016 Keywords: Gypsum stabilized adobe Marble dust Polypropylene fiber Compressive strength Flexural strength abstract Adobe is one of the oldest and most widely used building materials in the world. It is a natural building material made from sand, clay, water, and some kind of fibrous or organic material, such as sticks and straws. Alker is just soil with a high content of clay stabilized with lime and calcined gypsum. It is com- posed of 10% gypsum, 2% lime, and 20–22% water in veneration to the weight of dry soil as a construction material. Earthen structures are extremely durable when built using skilled production and design prin- ciples. The strength and durability of earthen materials can be improved, if needed. Some kinds of fibrous, inorganic, or organic materials, like sticks, straw, dung, rice husks, asphalt emulsion, Portland cement, and lime, can be added to promote earth stabilization. This study examines the effect of polymer fiber and waste marble dust contents on the compressive and flexural strength of Alker by using two soils from different locations. Mechanical properties of certain soil–fibers–marble dust combinations comprising different proportions of polymer fiber as 0.5%, 1.0%, 1.5%, and 2.0% and waste marble dust (by 10% and 20% dry weight of soil) were thoroughly investigated. The results showed that producing adobe samples with polymer fibers results in better mechanical prop- erties than Alker. The most desired results for both soils were obtained using a ratio of 0.5% polymer fiber and 10% marble dust. The mix proposed satisfies the minimum compressive and flexural strength requirements of ASTM and Turkish standards. Ó 2016 Elsevier Ltd. All rights reserved. 1. Introduction Earthen construction does not meet today’s requirements due to certain limitations such as low water resistance and low earth- quake resistance. Earth’s strength and durability can be improved, if needed. The dense forms of stabilized earthen construction have a high thermal mass and are able to store heat as well as provide long-term energy savings for cooling in summer and heating in winter; as a result, they provide bioclimatic comfort for health with suitable humidity, thereby balancing the indoor climate. Given earthen structures’ high thermal comfort and in light of the cultural characteristic properties of Cyprus, their sustainability is important. During ancient times, different building materials were used in Cyprus. In both the Luzinian (1192–1489) and Vene- tian periods (1489–1571), stone was the major construction mate- rial; however, during the Ottoman period (1571–1878), stone was used only for the ground floor, as adobe construction was employed for the upper floors of residential buildings. During the British period (1878–1930), stone was used as a structural material [1]. Sustainability requires resources to be conserved, the environ- ment to be protected, and a healthy environment to be maintained. Sustainable development responds to the needs of the present without abandoning the ability of future generations to supply their own needs. http://dx.doi.org/10.1016/j.conbuildmat.2016.12.172 0950-0618/Ó 2016 Elsevier Ltd. All rights reserved. E-mail address: apekrioglu@ciu.edu.tr Construction and Building Materials 134 (2017) 556–562 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat