Handbook for Bridge Inspections - TSP2

• Homogeneity of the binding agent
* Distribu tion of the aggregate (quality)
• Air content Idi stance between air bobbles? (durabil ity aga inst
frost)
• Cracking
Thin Section Analysis
A piece of fin e ground concrete nonnally measures 40 x 45 mm.
and is ground down to a th ickness of20-25 my. Apart from that
obtained from surface grinding, fin e grinding provides the fo llowing
addit ional information:
• Carbonisation
• Leve l of hydration (q ualitative)
* Type of aggregate
• Chemical reactions such as reaction to alkali
Scope
Acceptance Inspections and Major Inspections
Structural analyses sha ll not be carried.
Speciallnpections
Structural analyses are carried out only when required, e.g. suspected
reaction to alkali.
Advantages and
Disadvantages
Plane Ract ifying and th in section analysis are both good methods
for detennining concrete qua lity but are destructive, costly and
time consuming. They should only be considered if the possible
damage and its causes cannot be detennined using any other method
or when it is important to know the composition of the concrete.
Since only a small part of a structure is examined, it is vital that
representative dri ll ed cores are removed for analysis and that
wide-ranging conclusions arc not drawn from the analysis resu lts.
Figure 7.3-10: Analysis IIsing Thin Sec/ioll Me/hod
Equipment
• Core drilling equipment
• Laboratory analysis equipment