How polymers improve concrete floors

8 Problems caused by cementitious overlays

9 What reaction polymers can achieve, at a cost

10 Improvements with polymer dispersions

11 A very simple method of benchmarking of overlays

12 Protection against impact and chemical attack as a function of strength and layer thickness

13 The future: chemistry and robotronics

How polymers improve concrete floors
Possibilities today and prospects for the future - a pragmatic approach to the limitations of concretes

by Dipl.-Chem. Dr. Peter Seidler

5^th International Colloquium Jan 21-23, 2003

8 Problems caused by cementitious overlays

As it is too difficult to get a concrete surface - and this surface layer is what really counts - so that it is immediately "strong" and "smooth enough to wallpaper", often a second layer is applied, namely a cementitious overlay with a thickness of ≥ 10 mm and a weight of ≥ 20 kg/m². It may cause additional problems at the interface with the concrete sub-base. Stresses resulting from different thermal expansion and shrinkage can cause the overlay to debond. There is an old and venerable work dealing with the many reasons why a cementitious overlay can fail. They are shown in the following tables.

Types of damage

insufficiently hardened
is powdering, porous
shows cracks and breaks
is rough
is contaminated with oil or chemicals
is worn, has grooves

Causes and Responsibility

Construction management
Manufacturer
Contractor
External influences

Table 5: Types and causes of damages

Responsibility of construction management

premature stress
heating
radiant heat
draught

Responsibility of the manufacturer

bad grain-size distribution
too many fines
insufficient grain strength
too many filterable constituents
contamination
humus acids
swelling grains (such as marl or brown coal)
frozen sand
contaminated water
too small proportion of binder
too large proportion of binder
wrong proportion of additive
too much water
insufficient mixing

Responsibility of contractor

too long storage before placement
insufficient compaction
too early smoothing
too much smoothing
too little thickness
drying out not uniform
too large distances between joints

External influences

effect of frost during solidification and hardening
improper maintenance
improper use

Table 6: Responsibility of damages

Last Update: Jan 29, 2003

0 Abstract 1 We have all the means for better concrete 2 History of mortars and concretes 3 Costs of an industrial concrete floor 4 The meaning of "strength" and "resistance" 5 Some shortcomings of concrete 6 Miracles made of concrete, but not for industrial floors 7 Special cements for industrial floors with no shrinkage 8 Problems caused by cementitious overlays 9 What reaction polymers can achieve, at a cost 10 Improvements with polymer dispersions 11 A very simple method of benchmarking of overlays 12 Protection against impact and chemical attack as a function of strength and layer thickness 13 The future: chemistry and robotronics 14 References		How polymers improve concrete floors Possibilities today and prospects for the future - a pragmatic approach to the limitations of concretes by Dipl.-Chem. Dr. Peter Seidler 5^th International Colloquium Jan 21-23, 2003 8 Problems caused by cementitious overlays As it is too difficult to get a concrete surface - and this surface layer is what really counts - so that it is immediately "strong" and "smooth enough to wallpaper", often a second layer is applied, namely a cementitious overlay with a thickness of ≥ 10 mm and a weight of ≥ 20 kg/m². It may cause additional problems at the interface with the concrete sub-base. Stresses resulting from different thermal expansion and shrinkage can cause the overlay to debond. There is an old and venerable work dealing with the many reasons why a cementitious overlay can fail. They are shown in the following tables. Types of damage insufficiently hardened is powdering, porous shows cracks and breaks is rough is contaminated with oil or chemicals is worn, has grooves Causes and Responsibility Construction management Manufacturer Contractor External influences Table 5: Types and causes of damages Responsibility of construction management premature stress heating radiant heat draught Responsibility of the manufacturer bad grain-size distribution too many fines insufficient grain strength too many filterable constituents contamination humus acids swelling grains (such as marl or brown coal) frozen sand contaminated water too small proportion of binder too large proportion of binder wrong proportion of additive too much water insufficient mixing Responsibility of contractor too long storage before placement insufficient compaction too early smoothing too much smoothing too little thickness drying out not uniform due to strong sun radiation due to draught too large distances between joints External influences effect of frost during solidification and hardening improper maintenance improper use Table 6: Responsibility of damages
Last Update: Jan 29, 2003