Investigation of chitin effect on the properties of cement slurry as an example of chemical additive-biopolymer compatibility

In last decades, most of the academic studies focused on waste materials and their effects of human benefits. For this reason, the question on how we use these waste materials, has become popular. In this study as an answer of this question, biopolymers have been used as waste materials. In the scope of this study, the effects chitin biopolymers on the mechanical properties (such as flow and strength values) and the durability properties (such as freeze-thawing resistance) of cement mortars incorporating with three different chemical admixtures having different base, were investigated. Chitin were added to the cement mortars with the ratios %0,3 and %1,0 by cement weight. Furthermore, superplasticizers were added to the mixes with the ratios %0,4, %0,8 and %1,0 by cement weight. On the other hand, reference mortars without any admixtures and cement mortars with chemical admixtures were prepared. 4x4x16 cm prismatic molds were used to prepare cement mortar samples, and some experiments were performed at fresh and hardened states. To obtain strength values, samples were examined under bending test and compressive strength test after bending, at the ages 7 and 28. To obtain the effects of compatibility of biopolymers and superplasticizers at fresh state, flow tests were performed. To investigate the effects of environmental attacks on cementitous materials, cement mortars were examined under freeze and thawing tests at 25 and 50 cycles. The strength values were obtained. In our study, positive and negative effects of usage of chitin biopolymers with different based superplasticizers in concrete production were represented. The study indicates that the early ages and ultimate properties of concrete may be improved by using chitin with chemical admixtures with optimum ratios.