Module 2 - Control of Concrete on Site

Module 2

A two-day course for foremen and site engineers in the control of concrete on site.

Programme

DAY 1

Review of concrete properties

Strength grades

The trouble with water/cement ratio

Consistence

Cohesion, segregation and bleeding

Durability

Materials update

Cementitious materials

Properties of blended cements

Aggregates including “fines”

Admixtures, Additives and Additions

Concrete faults (1)

Construction defects

Blow holes

Honeycombing

Grout loss

Scour

Water runs & sand streaks

Laboratory practical exercise:

Trial mixes

Effect of changing the water/cement ratio

Slump testing

Flowing/self-compacting concrete

Air content

Cube making and curing

Demonstration – Cube testing

Concrete faults (2)

Non-structural cracking

Thermal cracking

Plastic cracking

Plastic settlement

Plastic shrinkage

Drying Shrinkage

Overnight syndicate project:

Early-age cracking.

DAY 2

 Syndicate reports

Outline of concrete types

Nominal mixes

Prescribed concretes

Standardized prescribed concretes

Designed concretes

Designated concretes

Proprietary concretes

Durability criteria

Concretes for specific applications

Selecting appropriate workability levels

Watertight construction

High quality surface finishes

Supervision of concrete construction (1)

Procurement of concrete

Checking and testing

What to do if the slump is wrong

Transporting concrete

Supervision of concrete construction (2)

Compaction

Over-vibration

Under-vibration

Secondary vibration

Curing

Conformity criteria (1)

Interpretation of test results

Evaluating test results

Comparing yesterday’s trial mixes

Conformity criteria (2)

Action on non-conformity

Contractor-specific topics

 Questions, answers and final discussion.