Get your money's worth
PROF. A.R. SANTHAKUMAR
| The plan should identify key elements necessary to provide fitness of
structure and the methods by which they are provided and quantitatively
measured |
CRUCIAL TASK: Building supervisor must keep a tab on all aspects of
construction
Most apartment buildings are made of RCC frames. The
properties of the completed structures should be consistent with the user
requirements and assumptions made during planning and design. This could be
achieved only by proper quality assurance measures.
Quality assurance in construction activity relates to proper
design, use of adequate quality materials and components supplied by various
vendors, proper execution of work by the contractor during construction and
proper care during the use of structure, including periodic maintenance and
repair by the user or owner. Everybody, from the planner, architect, designer,
to contractor, supplier of materials and the owner has a role to play. Only then
will the final structure have satisfactory strength, serviceability and
long-term durability.
Quality assurance involves both technical and organisational
aspects. The apartment project should have an explicit quality assurance plan.
This plan should identify key elements necessary to provide fitness of structure
and the methods by which it is provided and quantitatively measured. This will
give all the stakeholders the confidence that the realised project will work as
per norms in service, thus fulfilling the user needs. This will involve quality
checks (audit) of both inputs and outputs.
Quality
Audit
Inputs are in the form of materials, machinery and manpower.
Workmanship in all stages of batching, mixing, transportation, placing,
compaction and curing should be explicitly checked and recorded. The quality of
the final product will be satisfactory only if approved plants and machinery and
equipment for the process are used. All these should form part of the quality
assurance plan.
To ensure that the inputs comply with design an inspection
procedure should be set up covering materials, records, workmanship and
construction. Tests should be made on reinforcements and constituent materials
of concrete in accordance with Bureau of Indian Standards.
There should be clear instructions on inspection standards.
The elements should be checked against the design detail with due allowance for
dimensional tolerance.
To ensure proper performance each step in construction should
be inspected before the next step is taken. This should be followed as the work
proceeds.
Care should be taken to see that elements critical to
workmanship, structural performance, durability and appearance are identified
for special inspection. The system to verify the quality should include the
individual parts of the structure, especially the identified critical ones.
Supervision
Supervision at each step is a part of the plan. It is not
possible to alter concrete dimension, once placed. Hence constant and strict
supervision is a must during the progress of work. This should include all
aspects of concreting such as proportioning, mixing, placing and curing.
Supervision is of extreme importance to check the reinforcements and its
relative disposition before being covered by concrete.
Each and every contributor to the project should make and
implement a quality assurance plan with respect to the project. Supplier,
contractor and sub-contractors' participation should be covered by the overall
plan.
The individual agency's plan should fit as a part of the
overall plan. . The plan should define the tasks and responsibilities of all
agencies involved. It should state adequate checking procedures and the
organisational set-up for documentation. The documentation should necessarily
include the following:
1. Approved site layout plan.
2. Architectural plan.
3. Soil report and bore log data.
4. Structural design details with structural plan.
5. Test reports and manufacturers' certificate for materials,
concrete mix design details.
6. Pore cards for site organisation and clearance for
concrete placement.
7. Records for site inspection of workmanship.
8. Periodic field test results.
9. Non-conformance reports and correction actions taken.
10. Quality control charts.
11. Completion report with a maintenance scheme.
Quality control charts are necessary if concrete is in
continuous production over a long period of time. The owner should have a
periodic maintenance plan to ensure long and trouble-free service from the
quality structure. Maintenance is also required to keep the structure in a fit
condition to resist unexpected overloading due to disasters such as earthquakes
and cyclones. This will also reduce the life cycle cost of the structure.
The author is Emeritus Professor, Department of Civil Engineering, IIT, Madras,
and former Dean, Anna University.
Courtesy: Property Plus, The Hindu
http://www.hindu.com/pp/2007/04/28/stories/2007042800750400.htm
