3. Concrete Joints
• Agricultural Waste Management Field
Handbook
• Notice WI-25, January 2005
• Companion Document 313-11
Control
Isolation
Expansion
Construction
4. Control Joints
• Control (contraction) Joints
– Control the location of cracks caused by
concrete shrinkage.
– Joints are made liquid tight using embedded
waterstop.
– May coincide with a construction joint.
– Sawcuts or joint formers should be 1/3 of slab
thickness.
6. Expansion/Isolation Joints
• Expansion / Isolation Joints
– Separate or isolate abutting concrete.
– Protects movement of one concrete structure
from damaging abutting structure.
– Allows some differential movement at the
joint.
– Liquid tight with waterstop and expansion
material.
8. Construction Joints
• Construction Joints
– Stopping places during construction.
– Located where a new pour of concrete abuts
existing concrete.
– May be predetermined locations or as
needed.
– Typical locations include the base of walls
and in large slabs or walls.
– May also function as control and/or expansion
joints.
9. Construction Joints (cont.)
– If reinforcing steel is carried through the joint,
the joint surface of the first pour is cleaned
properly, and the second pour is well
consolidated at the joint, these joints are
considered liquid tight.
12. NOT GOOD –
NO EXPOSED AGGREGATE
GOOD –
EXPOSED AGGREGATE
Construction Joints (cont.)
• Joint shall be cleaned to expose aggregate but
don’t displace aggregate.
13. • Steel plate does NOT make the joint
liquid-tight.
• Keyway does NOT make the joint
liquid-tight.
• Joint must be cleaned with aggregate
exposed to be liquid-tight.
Wall Joint (at base of wall)
14. Tank Walls
• Tank walls are designed with the base
being a “flexible” joint. This requires the
use of a waterstop.
• 4” is used on NRCS standard reception
tank drawings.
19. Joint Spacing (cont.)
• Beside minimum spacing where else
should joints go?
• Corners, base of slopes, irregular shapes
• NOT across the side slopes.
20. Wisconsin Minimum Design and
Construction Standards for Concrete
Mixing and Loading Pads and Secondary
Containment Structures
David W. Kammel
Professor, Biological Systems Engineering Department
University of Wisconsin Cooperative Extension
Published February, 2005
23. Waterstop Placement Parameters
w
j
t
y
x
a
b
a = largest aggregate size
b = reinforcement
w not greater than t
w not less than 6a + j
x not less than 2a
y not less than 0.5(w – j)
d = differential movement
ID = inside diameter of centerbulb
ID <= d (conservative)
24. Waterstop Joint Details
• Currently no standard details allow for a
continous pour.
• Working on developing acceptable
alternative to make this work.
29. Joints in Waterstop
• Provide factory fabricated waterstop
corners and transitions leaving only
straight butt joints for field fabrication.
• Use only a manufacturer’s recommended
splicing iron.
• Adhesives, solvents, lapping and edge
welding are NOT acceptable.
32. Waterstop Plan
• Calculate quantities of waterstop needed.
• Calculate number of pre-manufactured
joints.
• Determine if hydrophilic waterstop is
required and how much.
• Alterations to plan need to be approved by
the engineer.
33. Inspection Plans/
Preconstruction Meetings
• Many construction problems can be avoided with
properly prepared construction inspection plans &
preconstruction meetings.
• Inspection Plan – detailed list of what needs to be
inspected, who needs to do the inspection, and
when inspections are needed.
• Preconstruction Meeting – make sure all
contractors, engineer, and landowner are on the
same page.
34. Inspection Plans
• WHO – Identify who is responsible for the
individual inspection items.
Be specific: name the individual person.
There may be different people needed for
different inspection items.
35. Inspection Plans
• WHAT – Identify what needs to be inspected.
Be specific.
THIS:
– Verify 12” dia. PVC, Schedule 40, ASTM D1785
NOT:
– Document the size and type of pipe.
36. Inspection Plans
• WHEN – Identify when inspectors need to be
on-site.
EXAMPLE:
– Site must be inspected after waterstop forming and
prior to concrete placement.
37. Preconstruction Meeting
• Make sure everyone knows what materials
are acceptable.
• Verify availability of pre-manufactured
joints.
• Review waterstop plan.
• Review placement and consolidation
needed (vibration).
• Review joint details and pour sequencing.
