Quality is important part of construction but managing it at site is very difficult task for any organization. Some importance insights for civil engineering students who are not aware of.
2. Idea about quality in costruction.
Importance & Cost of quality.
Quality Assurance & Quality Control.
Elements of quality.
Quality assurance techniques (inspection, testing, sampling)
Changing views of quality.
Objectives of the chapter:
3. Construction Quality - Introduction
Construction project quality:
The fulfillment of the owner’s needs as per the defined scope of work within the budget and
specified schedule to satisfy the owner’s/user’s requirements.
Construction Quality Management is different from traditional production quality management
because
Every project is unique nature - Mostly outdoors
Contractual Obligations and Commitments - Engineering & Procurement Contract, BOT etc.
Costly and Large outputs - Difficult to rectify.
Multiple interfaces and involvement of large number of participants – Designer, Client,
Contractor, PMC, Sub-contractor etc.
Inherent risks - Variable location, specifications, time, scope, cost.
Quality
Inspection
Quality
Control
Quality
Assurance
Quality
Engineering
Quality
Management
Evolution of Quality Management
4. Quality Control & Quality Assurance
• Quality control in construction projects can be defined as checking of executed/installed works
to confirm that works have been performed/executed as specified, using specified/approved
materials, installation methods and specified references, codes, standards to meet intended use.
• Quality assurance in construction covers all activities from design, development, production/
construction, installation, and servicing to documentation, and also includes regulations of the quality
of raw materials, assemblies, products, and components; services related to production; and
management, production, and testing/inspection processes.
Quality Assurance Quality Control
• A systematic set of activities to provide confidence
the requirements are established
• The process by which quality is compared by
applicable standards
• Prevents introduction of issues and defects • Detects, reports and corrects defects
• Establishes and evaluates the processes • Verifies if the product meets the predefined
standards
• Improves the process to produce an output • Improves the development of the product or output
Difference Between QA & QC
5. Importance of Quality in Construction
Achieving customer satisfaction – Repeat Orders
Continuous improvement – Capability Enhancement
Developing teamwork – Learning Curves
Establishing a vision for the employees – Career Building
Setting standards and goals for the employees – Training
Building motivation within the organization – Competition
Developing a corporate culture – Project based Business
Cost of prevention of defects
Cost of detecting the defect
Cost of rejection and rework
Cost of reliability and warranty claim
Cost of Quality
7. Fish Bone Diagram Analysis
CASE : Users complain about suppliedwater
7
USERS
COMPLAIN
Quality of Water
General
Structural
Water Pressure
HEALTH ISSUES
Source water
quality
Poor source
water quality
BAD TASTE
High
Chlorine
Presence of sick
residence
LOW PRESSURE
Pressure
Release valve
failure
Leakage
NO WATER
Main Pump
Station Failure
Non operational
Booster Pump
Unplanned
Maintenance
WATER VISIBLE AT SURFACE
OVER USEAGE
Leakage Issue
Social Irresponsibleness
Drainage Issue
COLOUR OF WATER
High Turbidity
Storage
Cleanness
Pumping Issue
SURVICE CONNECTION
Valve failure
Minor
Repair
Replacement of
Braked/Rusted
Line
Plumbing Issue
from owner
side
Leakage in
Pipeline
WATER LEAK
Leakage in
Valve
Codification:
Main Issue
Level 1 Cause (Major)
Level 2 Cause (Minor)
Level 3 Cause (Root)
8. Quality Assurance Techniques
“those planned and systematic actions necessary to provide adequate confidence that product or
service will satisfy given requirements for quality.” – ISO 9000
Quality assurance is the third era in the quality management system.
Gained recognition after WW II when military production technology was utilized in civilian services.
•Ensure the
work done
with the plan
•Action to
correct the
error if any
•Develop how
to work out
plan and
perform
•Decide what
is to be done
QualityCyclePDCA
Cycle
9. A component or product, which is manufactured, is required to perform certain functions. The act of
checking whether “a component actually does the intended job or not” is called Inspection. It’s strength,
hardness, shape, surface finish, chemical composition, dimensions etc. may specify product quality.
Reasons of Inspection
Problem (or defect) Identification or Forecast,
Problem (or defect) Prevention,
Problem (or defect) Elimination.
Inspection
Inspection
Based on the
Quantity of
Inspection
Census
or
100% Inspection
Sampling
Inspection
Based on the
Stage of
Inspection
Inward or
Receipts
Inspection
Regular Interval
Inspection
or
Routine Inspection
Critical Point
Inspection
or
Stage Inspection
Outward or
Final
Inspection
Roving Inspection
or
Patrolling
10. Sampling
Sampling
Random
Sampling
Unrestricted
Random
Sampling
Stratified
Sampling
Systematic
Sampling
Cluster or
Multi Stage
Sampling
Non-Random
Sampling
Judgment or Purpose or
Deliberate Sampling
Convenience
Sampling
Quota
Sampling
Sampling is the selection of a subset or few number of individuals from within a large number to estimate
characteristics of the whole. It has used in statistics, quality assurance, and survey methodology.
Reason of sampling instead of whole inspection
When inspection cost is very high
When there is uniformity in the items of the lot
When there is homogeneity
When the population is very large
For life testing (accelerated run)
If the test is destructive in nature
11. Testing
Tests on Soil Subgrades
Shear Tests: Direct Shear Test, Tri-axial Compression Test, Unconfined Compression Test, Vane Shear
Test.
Bearing Tests: Plate bearing tests.
Penetration Tests: California Bearing Ratio Test, Cone Penetration Test.
Aggregate Properties and Tests
Property Explanation Test
Strength Resistance to crushing Crushing Test
Hardness Resistance to abrasion Los Angeles Abrasion Test
Toughness Resistance to impact Impact Test
Shape Better workability, interlocking and strength Shape Test
Soundness Resistance to weathering Soundness Test
Specific Gravity Measure of strength and presence of voids Specific Gravity Test
12. Other Tests on Aggregates
Specific Gravity and Water Absorption Test: Specific Gravity should lie between 2.6 to 2.9 & water
absorption should be < 0.6%
Soundness Test: Soundness test is intended to study the resistance of aggregates to weathering
action, by conducting accelerated weathering test cycles.
Flakiness Index Test: Flakiness Index is the percentage weight particles by total weight of aggregates
whose least dimension is 0.6 times the mean dimension.
Elongation Index Test: Elongation Index is the percentage weight particles by total weight of
aggregates whose greatest dimension is 1.8 times the mean dimension.
Tests on Cement Concrete
Test for workability of fresh concrete – Slump Test.
Tests on hardened concrete – Cube Test.
Non Destructive Tests
1. Rebound Hammer Test.
2. Penetration and Pull out techniques.
3. Dynamic or vibration tests.
4. Radio active and nuclear methods.
5. Magnetic and Electrical methods.
13. Tests on Asphalt / Bituminous Concrete
Penetration test…. for testing hardness or softness
Ductility test…. for adhesiveness & elasticity
Viscosity test…. for measuring resistance to flow
Float test…. to define the consistency
Specific gravity test…. for knowing mass / weight
Softening point test…. temperature at which it softens (35 degto 75 deg)
Flash point test…. lowest temperature at which takes fire momentarily
Fire point test…. lowest temperature at which it ignites and burns
Solubility test…. for testing impurities
Spot test…. to determine over heated or cracked bitumen
Water content test…. to know the water content
Bitumen content test…. to know the bitumen content
