Use of textile, paper and natural stone industry wastes in structural and non-structural lightweight concrete production

In parallel with the increasing human population all over the world, people's needs are constantly increasing. This situation brings industrialization in almost every field. By-products and industrial wastes resulting from industrialization can cause environmental problems that can be considered dangerous. Efforts to both reduce the negative effects of industrial waste on the environment and to bring waste into the economy by recycling and reusing it in different areas continue to increase. In this study, the largest grain diameter (Dmax) of waste Bayburt tuff aggregate was determined as 11,2 mm in order to make a comparison with perlite used in the market. It was aimed to produce structural (SLC) and structural lightweight concrete (NSLC) by using solid lignin (L) obtained from paper mill waste and reactive dyestuffs (RD) obtained from wastewater of textile factories as concrete additives. Solid lignin was obtained by precipitating and drying the lignin liquor obtained from paper mill waste in an acidic environment. Waste reactive dyes used in textile dyeing were prepared as model solutions. Lightweight concrete mixtures produced from textile, paper and natural stone industry wastes were poured into molds measuring 10×10×10 cm and compressive strength tests were applied to the samples after 7, 28 and 90 days. It was aimed to produce lightweight concrete with a compressive strength of at least 30 MPa for SLC (in TS 206, LC25/28) and a minimum of 5 MPa for NSLC. Bayburt stone (BS), which was targeted for industrial evaluation, was prepared in granulometry in accordance with Turkish Standards (TS) 802, Dmax 8 mm and significantly compatible with the Fuller curve. SLC mixtures were prepared using BS aggregates, with a fixed cement dosage of 450 kg/m3, a constant slump (S2, 5-9 cm) and a constant water/cement ratio of 0,50. Strength tests were performed on samples cured in lime-saturated water for 28 days. Hydration of concrete prepared using waste materials was monitored by mechanical tests, XRD, EDS, SEM, DTA/TG/DTG techniques. As a result, it was determined that Bayburt yellow stone (BYS) aggregate cannot be used in lightweight concrete production due to its lack of pozzolanic properties, high unit weight (UW) value (2,06 g/cm3), and low inherent strength. However, it can be successfully used as a standard concrete aggregate. Bayburt white stone (BWS) aggregate, with its pozzolanic properties, high inherent strength, and UW value of less than 2 g/cm3, can be successfully used directly in lightweight concrete production. Furthermore, it was determined that BWS aggregate can also be successfully used in SLC production due to its strength improvement when stored in lime and soda-saturated environments. It was determined that adding 0.6% lignin and 0.04% RD to the mixtures increased the strength of the concrete by acting as a superplasticizer (SP). Furthermore, RDs permanently colored the concrete. This approach not only eliminates environmental problems caused by waste but also allows for industrial utilization of the waste. It was determined that when BWS was ground to a 0-0.063 mm particle size and incorporated into the cement up to 30%, there was no significant decrease in the 90-day strength of SLC and NSLC.