This document discusses the key ingredients and raw materials used in ordinary concrete, including the optimal water content. The main ingredients are cement, fine aggregate (sand), coarse aggregate (gravel), and water. Fine aggregate fills the spaces between coarse aggregate. Cement acts as the binding agent when mixed with water through hydration. The optimal water-cement ratio is important - too much water reduces strength, while too little reduces workability. Two common methods for calculating raw material quantities are discussed: 1) based on experimental dry-wet ratios and material unit weights; and 2) using yield and cement factor thumb rules.