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:red_flag:HARDENED CONCRETE - Coggle Diagram
:red_flag:HARDENED CONCRETE
Factors affecting concrete strength
1. Influence of the constituent material
Cement
Water
Aggregate
Admixture
2. Degree of compaction
Proper compaction increase strength
3. Influence of curing
Used for promoting the hydration of cement and consist of a control of temperature and moisture movement from and into the concrete
Properties of hardened concrete
Durability
Defined as its resistance to deterioration processes that may occur as a result of interaction with its environment (external) or between the constituent material or their reaction with contaminants present (internal)
Permeability
Concrete has tendency to be porous due to the presence of void formed during or after placing
Deformation under load
Stress-strain relationship under normal loading and under sustained loading
Shrinkage
Caused by the settlement of solid and the loss of free water from the plastic concrete (plastic shrinkage), by the chemical combination of cement with water and by the drying of concrete
Strength
Defined as the maximum stress it can resist or the maximum it can carry
Cubes, cylinder and prism are the 3 types of compression test specimen
Flexural tensile test - to estimate the load at which the concrete member may crack
Concreting in different enviroment
Concreting in sea water
May damaged by crystallization of salt inside the mass in zones where the concrete subjected to is alternate wetting and drying
Reinforce concrete is much more open to damage due to corrosion of reinforcement
A dense concrete cover prevent sea water from penetrating into the concrete and thereby protects the steel against corrosion
Testing of hardened concrete
Destructive test (DT)
Compression
Flexural
Splitting
Non destructive test (NDT)
Ultrasonic pulse velocity (UPV)
Rebound hammer
Durability of concrete
Ability to with stand the damaging effect of the environment over a long period of time
The existence of durability maybe caused either by the environment to which the concrete is exposed