CVG 2141 Lecture Notes - Lecture 3: Corrosion, Nondestructive Testing, Modulus Guitars

• School: University of Ottawa
• Department: Civil Engineering
• Course: CVG 2141
• Professor: Abdulridha Alaa

Document Summary

Additional ingredients in a mix design that can be added right after or during mixing. Pros of using admixtures: cost efficiency, to gain desired qualities, maintain quality of concrete (during bad weather), overcome emergencies during projects (sudden time constraints, trial mixes should be made to confirm effectiveness of admix. Types: chemical (<4%), mineral (>10% ) ** both depend on weight of cement. Types of chemical admixtures: (memorize-the red ones: accelerators: for early setting & early strength development. Efficient plugging leaks (from hydraulic press. : retarding: slows doen setting and hardenging time. Discontiuities for large slabs should be avoided. Can reduce early strength: water reducing: reduces amount of water to promote high slump. Increased workability, higher f"c, no segregation, less shrinkage. Normal range (5-7% reduction), mid range (up to 12%), high (12-30%: flowing concrete: concrete + superplasticizers. Applications: for thin placements, areas w/ a lot of reinforcement, underwater, to reduce handling cost: air entraining: introduces microscopic airbubbles in the structure.