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The optimal mixing conditions for semiplastic recycled cold asphalt, which recycled waste asphalt and used noncement binders (NCB), were assessed through verification of the performance. The NCB of 6% desulfurization gypsum mixing was found to have the most outstanding properties. For the Marshall stability, 4% (NCB) filler mixing brought about a 1.92-time strength increase effect compared to OPC (2%) and was improved when using modified asphalt and SBR. The flow test results showed that although an increase dosage of filler and SBR decreased the flow value of the semiplastic recycled cold asphalt, an increase dosage of asphalt emulsion improved the flow value. The indirect tensile strength and liquid immersion residual stability for the condition with greatest Marshall stability were most outstanding with 0.95 MPa and 83.6%, respectively. Evaluation of the recycled cold asphalt abrasion durability revealed that for the case of mixing more than 4% NCB the mass loss rate was lower than 20%. The abrasion durability was found to improve when using modified emulsified asphalt and SBR substitution. From the test results, it was found that the optimal mixing proportion of semiplastic recycled cold asphalt satisfied mechanical properties and durability is NCB with 4%, emulsified asphalt with 3%, and SBR substitution with 20%.

In the recent design of a sustainable high ductile fiber-reinforced cementless composite, optimizing both sustainable and mechanical properties is critical. The purpose of current research is to develop a sustainable material while maintaining high ductility, represented by strain-hardening behavior in tension. The sustainable material is referred as a sustainable high ductile fiber-reinforced cementless composite which is manufactured using ground granulated blast-furnace slagbased alkali-activated cementless binder mixing with poly vinyl alcohol fibers. Three mixture proportions which had proper flowability and viscosity in fresh state in order to mix easily and disperse fibers uniformly were determined according to alkali activators and admixtures. A series of experiments on compression, direct-tension, and panel bending responses were carried out on the hardened composites. The fresh composites showed an average of 465 mm slump flow, the hardened composites were able to obtain the tensile strain up to 2.8%, and the ratio of bending deflection to span length was up to 14.3% with multiple micro-cracks.

This study examined the results of SEM and XRD analyses of cementless concrete mixed with chemical gypsum, a byproduct of oil refineries. The results suggest that cementless concrete at early age creates ettringite, calcium hydroxide, and C-S-H gel more slowly than does OPC concrete, but at the age of 28 days, it was found to have similar fine structures and densification level of structures. In addition, it was observed that ettringite and other crystalline structures were more actively produced at curing temperature of 40°C compared to 20°C.

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