Study on pozzolanic activity of porphyrites of the Karatau deposit Azamat Khadzhiev, Farrukh Atabaev, Arslon Jumaniyozov and Yusufboy Yakubov E3S Web Conf., 563 (2024) 02029 Published online: 30 August 2024 DOI: 10.1051/e3sconf/202456302029