Enhancing sustainability: Mix design, mechanical properties and durability of alkali-activated slag-dolomite concrete modified with crumb rubber

In the past two decades, geopolymer concrete or GPC was developed as an ecologically friendly substitute to cement concrete , presenting the opportunity to reduce the substantial CO 2 emissions linked to cement manufacturing. The present work attempts to evaluate the design of mixes, mechanical qualities, and durability of Ground granulated blast furnace slag-dolomite rubberised geopolymer concrete (GDR-GPC). GGBS and dolomite powder were utilized as binders in geopolymer concrete, with GGBS facilitating ambient curing and dolomite aiding early strength attainment. NaOH and Na 2 SiO 3 solutions were combined and used as the alkalis for the development of GPC. The study involves binary GPC mix design utilising the Taguchi approach to maximize compressive and impact strength . Subsequently, the fine aggregate portion of the optimized GPC is replaced by rubber particles. Crumb rubber (CR), generated through the ambient grinding process of discarded waste tyres, represents a potential source of environmental pollution . It is utilized as a substitution at volume percentages of 5 %, 10 %, 15 %, and 20 % fine aggregates. The performance of the GDR-GPC is analysed according to its workability, dry unit weight, stress-strain behaviour, flexural strength , split tensile strength and impact strength . The formulated sustainable GDR-GPC mixes demonstrate acceptable hardened properties. The compressive strength ranges from 52.14 to 63.58 MPa when crumb rubber replaces fine aggregates in volumetric proportions between 20 % and 5 %. The impact energy and elastic modulus of the GDR-GPC mix with 20 % crumb rubber replacement are 2236 J and 15.41 GPa, respectively. This could create a substantial market for GDR-GPC products in applications that emphasize enhanced impact strength and flexibility, such as impact-resistant barriers and railway sleepers.