causet he calcium oxideo rh ydroxide to be removed, lowering the pH
of the cement mix, will cause instability and solution of the cement hydrates.
The most commonc ause for the deteriorationo fc oncrete results from
contactw ith inorganic and organic acids. Those that form solubles alts
with calcium oxide or calcium hydroxide are the most aggressive. Typical
compounds that can cause problems include sour milk, industrial wastes,
fruit juices,s onic ultrapure waters,a nd organic materials that ferment and
produce organic acids. Typical chemical families found in various types of
chemical processing industry plants and their effect on concrete are shown in
Table 10.1.
10.1S urface Preparation
It is essential that the concrete surfaceb ep roperty prepared prior to
application of the coating. The surfaces of cement containing materials
may contain defects that requirer epair before the applicationo ft he
coating. In general, the surfacem ust be thoroughly cleaned and all cracks
repaired.
Unlike specifications for the preparation of steel prior to coating, there
are no detailed standard specifications for the preparation of concrete
surfaces. In most instances, it is necessary to follow the instructionssupplied
by the coating manufacturer.S pecifications can range from the simple
surface cleaning thatp rovidesacleans urface without removing
concrete from the substrate, to surface abrading that provides ac lean
rougheneds urface,t oa cide tching that also provides ac lean
roughened surface.
10.1.1S urface Cleaning
Surface cleaning is accomplished by one of the following means:
1. Broom sweeping
2. Vacuum cleaning
3. Air blast
4. Water cleaning
5. Detergent cleaning
6. Steam cleaning
Water cleaning and detergent cleaning will not remove deep embedded soils
in the pores of the concrete surfaces. In addition, these methods saturate the
concrete that then requires ad rying period (not always practical).
Corrosion of Linings and Coatings
516
CAT8247—CHAPTER 10—6/10/2006—12:52—SRIDHAR—XML MODEL B–pp. 515–532
of the cement mix, will cause instability and solution of the cement hydrates.
The most commonc ause for the deteriorationo fc oncrete results from
contactw ith inorganic and organic acids. Those that form solubles alts
with calcium oxide or calcium hydroxide are the most aggressive. Typical
compounds that can cause problems include sour milk, industrial wastes,
fruit juices,s onic ultrapure waters,a nd organic materials that ferment and
produce organic acids. Typical chemical families found in various types of
chemical processing industry plants and their effect on concrete are shown in
Table 10.1.
10.1S urface Preparation
It is essential that the concrete surfaceb ep roperty prepared prior to
application of the coating. The surfaces of cement containing materials
may contain defects that requirer epair before the applicationo ft he
coating. In general, the surfacem ust be thoroughly cleaned and all cracks
repaired.
Unlike specifications for the preparation of steel prior to coating, there
are no detailed standard specifications for the preparation of concrete
surfaces. In most instances, it is necessary to follow the instructionssupplied
by the coating manufacturer.S pecifications can range from the simple
surface cleaning thatp rovidesacleans urface without removing
concrete from the substrate, to surface abrading that provides ac lean
rougheneds urface,t oa cide tching that also provides ac lean
roughened surface.
10.1.1S urface Cleaning
Surface cleaning is accomplished by one of the following means:
1. Broom sweeping
2. Vacuum cleaning
3. Air blast
4. Water cleaning
5. Detergent cleaning
6. Steam cleaning
Water cleaning and detergent cleaning will not remove deep embedded soils
in the pores of the concrete surfaces. In addition, these methods saturate the
concrete that then requires ad rying period (not always practical).
Corrosion of Linings and Coatings
516
CAT8247—CHAPTER 10—6/10/2006—12:52—SRIDHAR—XML MODEL B–pp. 515–532