CONSRUCTION MATERIALS - SEMESTER 1 STUDY NOTES.
Prepared by : Daltone Majabe.
Institution :Kabete National Polytechnic.
Course :Diploma in Civil Engineering.
Year :2025.
Introduction.
Topic 1 :Cement.
Defination :
Cement is a fine grey powder that when mixed with water,forms a paste which hardens and
binds sand and stones into a solid mass.
Main Ingredients.
Lime (CaO)
Silca (SiO2)
Alumina (Al2O3)
Iron Oxide (Fe2O3)
Gypsum (CaSO4.2H2O)
Types of Cement.
Type of cement Main feature Common use
Ordinary Portland cement General purpose Building bridges
Rapid Hardening Cement Gains strength quickly Road repairs
Low Heat Cement Producess less heat Large dams
Sulphate Resisting Cement Resists chemical attacks Foundation in sulphate soil
Hydration Process.
Defination :
Hydration is the chemical reaction between cement and water that leads to hardening.
Stages.
1. Initial reaction - stiffens (setting starts)
2. Dormant period - workable mix for placement.
3. Hardening - formation of C-S-H gel and calcium hydroxide.
Key Points
Always cure concrete to maintain moisture and allow full hydration
Uses of cement.
Concrete production.
Mortor for masonary work.
Plastering.
Flooring and finishing.
C 2025 Majabe Study Guides | For Educational Use Only
Prepared by : Daltone Majabe.
Institution :Kabete National Polytechnic.
Course :Diploma in Civil Engineering.
Year :2025.
Introduction.
Topic 1 :Cement.
Defination :
Cement is a fine grey powder that when mixed with water,forms a paste which hardens and
binds sand and stones into a solid mass.
Main Ingredients.
Lime (CaO)
Silca (SiO2)
Alumina (Al2O3)
Iron Oxide (Fe2O3)
Gypsum (CaSO4.2H2O)
Types of Cement.
Type of cement Main feature Common use
Ordinary Portland cement General purpose Building bridges
Rapid Hardening Cement Gains strength quickly Road repairs
Low Heat Cement Producess less heat Large dams
Sulphate Resisting Cement Resists chemical attacks Foundation in sulphate soil
Hydration Process.
Defination :
Hydration is the chemical reaction between cement and water that leads to hardening.
Stages.
1. Initial reaction - stiffens (setting starts)
2. Dormant period - workable mix for placement.
3. Hardening - formation of C-S-H gel and calcium hydroxide.
Key Points
Always cure concrete to maintain moisture and allow full hydration
Uses of cement.
Concrete production.
Mortor for masonary work.
Plastering.
Flooring and finishing.
C 2025 Majabe Study Guides | For Educational Use Only
