Cons Mat 1 Flashcards
Quality control program
Specification
Standards
Testing
Followed Standards
AMERICAN SOCIETY FOR TESTING & MATERIALS
AMERICAN ASSOCIATION OF STATE HIGHWAYS & TRANSPORTATION OFFICIALS
AMERICAN CONCRETE INSTITUTE
PHILIPPINE NATIONAL STANDARDS
NATURAL STRUCTURAL CODE OF THE PHILIPPINES
Meaning of ASTM
AMERICAN SOCIETY FOR TESTING & MATERIALS
Meaning of AASHTO
AMERICAN ASSOCIATION OF STATE HIGHWAYS & TRANSPORTATION OFFICIALS
Meaning of ACI
AMERICAN CONCRETE INSTITUTE
Meaning of PNS
PHILIPPINE NATIONAL STANDARDS
Meaning of NSCP
NATURAL STRUCTURAL CODE OF THE PHILIPPINES
Determine whether the material should be allowed to be incorporated or be rejected into the work
material testing
Documented proof of the quality of materials
material testing
Tool for measuring quality control in project implementation
material testing
How materials are represented by a test
In accordance with the minimum testing requirements
Additional number of test can be required
Quality test of cement
1-Q every 2000 bags or fraction thereof
Quality test of CHB
1-Q every 10000 pcs or fraction thereof
Judgement by the costumer or users of a product or service
Quality
Extent to which the costumer or user feels the product or service surpasses their needs and expectations
Quality
Characteristics of a product that provides a level of performance in terms of service and life
Quality
Used in relation to something in need of checking or regulating due to some important and compelling reasons
Control
Used to correct something which has gone wrong or in other words.
Control
Is instituted as a corrective measure
Control
Widely and increasingly used in most industries to gauge the performance and excellence of work and product
Quality control
Purpose of Quality control in project 1
Insure the highest quality of work and extend the service life of any structure by constructing according to the prescribed plans and specifications
Indicate the specific type of the structure
plan
Present the characteristic in which it is built, as well as the materials that are to be incorporated into the work
Specifications
Purpose of Quality control in project 2
To check and regulate the use of construction materials and to economize on the cost of construction
Normally, every material should be subjected to?
testing
Inspection
and verification before acceptance
Who’s responsibility is Quality Control?
Everyone involved in the construction
as well as
the contractor’s engineers, inspectors, technicians, and even an ordinary laborors
Used in DPWH standards
Specifications
Applies to the written contract documents which includes material and workmanship requirements, inspection, and testing procedures and procedures for measurement and payment of the work.
Specification
Functions of specifications under the respect to the owner and his engineer
obligation to define material and workmanship requirements
Inspection and testing during the period of execution to indicate how work will be measured and paid for
Functions of specifications under the respect to the contractor
Obligation of complying with the contract requirements during the construction period
Meaning of GPC
Grading Plasticity Compaction
The prescribed tests on the construction materials to be used in a project based on approved contract quantities
Minimum testing requirements
The requirements which specify the kind and number of tests for each pay item of works
Minimum testing requirements
What is item 200 and 201
Sub base course
Base course
An unconsolidated or loose, combination of organic and inorganic materials
Soil
Organic materials of soil
Many time life forms that inhabit or live in the soil
Inorganic components of soil
Rocks and Minerals that have been gradually broken down by weather, chemical action and other natural processes
Considered a three-phase material composed of rocks or mineral particles, water and air.
Soil
Engineering properties of soil
Shear Strength
Stiffness
Permeability
Include shallow and deep doundation
Foundation built for above-ground structures
Includes earth-filled dams and retaining walls
Retaining Structures
Include embankment, tunnels, dikes, reservoirs, and sanitary landfills
Earthworks
Engineering Classification of Soil
A. Granular soil
B. Fine- grained soil
C. Organic soil
Passing 75mm (3’’) and retained on 0.075mm (#200) sieves
Granular or course-grained
May be crushed or natural angular particles and passing 75mm and retained on 2.0mm (#10) sieves
Stone
Rounded particles passing 75mm and retained on 2.0mm sieves mostly found in rivers
Gravel
Passing 2.0 mm and retained on 0.075mm sieves
Sand
(+) 2.0mm
(-) 0.425mm (#40)
course Sand
(+) 0.425 mm
(-) 0.075 mm
Fine sand
Granular Soil
Good load bearing qualities
Permeable, hence they drain easily
Comparatively incompressible when subjected to static loads
Not subject to changes in strength or volume due to variation in water content
Will undergo considerable reduction in volume if subjected to vibratory loads
Loose granular materials
Passing 0.075 mm and larger than 0.002 mm (fine and barely visible grains
Silt
Passing 0.002mm and larger than 0.001mm (cohesive or plastic)
Clay
Fine-Grained soil
Poor load sustaining qualities
Highly impermeable
Compressible under a sustained load
Subjected to changes in volume and strength due to variation in water content.
Passing 0.001 mm (gray to black color)
Organic soil
Organic soil
Inferior than fine grained soils with respect to the properties
Fibrous soil due to the presence of under composed plant matter
Unhealthy sewage-sludge odor
Found as deposits in swamps and peat bogs.
Soil containing qualities of organic material such as grass, roots, and sewage
Unsuitable soil material
Highly organic soil such as peat and muck
Unsuitable soil material
Soil with liquid limit exceeding 80 and/or plasticity index exceeding 55
unsuitable soil material
Soil with natural water content exceeding 100%
Unsuitable soil material
Soil with very low natural density, 800 kg/m^3 or lower
Unsuitable soil material
Soil that can not be properly compacted as determined by the engineer
Unsuitable soil material
Formula for plasticity index
PI = LL -PL
Formula for water content
[(Weight of wet soil - dry soil) / weight of dry soil ] x 100
Equally as important as the testing and the sampler shall use every precaution to obtain samples that will show the nature and condition of materials which they actually represent
Sampling
Occupies a very important place in determining the availability and suitability of the largest single constituent entering into the construction
Sampling of potential soils and soil aggregates sources and types
Sampling from undisturbed quarries
- Take sample separately from all strata that appear in color, texture and structure
- Proper identification of each sample as to location, color and texture is necessary as per sample card required.
Sampling from commercial source stockpile
- Remove first the outer layer of the stockpile until the damp material is reached and take the sample
- Take samples from different section of the stockpile and mixed it thoroughly as one sample, as a representative sample
Minimum testing requirement for Coarse aggregate
1 (sample)
1500 cu.m.
Minimum testing requirement for fine aggregate
1 (sample)
1500 cu.m.
Minimum testing requirement for Soil aggregate
none
Minimum quantity requirement for Coarse aggregate
70 kg
Minimum quantity requirement for fine aggregate
50kg
Minimum quantity requirement for soil aggregates
none
Preparation of samples for testing
Samples shall be dried thoroughly in air or in drying apparatus at a temperature not to exceed 60 degrees Celsius
Reduction of samples for laboratory Testing
Quartering
Sample Splitter
Laboratory tests for Granular soil sample
Grading/sieve analysis
Atterberg limit test (plasticity test)
Moisture- density relation test (compaction test in preparation for field density test)
California bearing ratio (CBR)
Abrasion test
Determine the particle particle size distribution of soil and it is used to classify/identify the soil
Particle size analysis of soils
3 Particle size analysis of soils
Sieve/grading test
Hydrometer test
Or a combined analysis
Sieve/grading test procedure
- Pass the sample through a series of sieves
- Sieve the samples until not more than 1% by weight of the residue passes the sieve within 1 minute
- Weigh and record the quantity retained on each sieve
Meaning of CCS
Concrete Cylinder Sample
AASHTO T23
Sampling of Concrete
Use of Concrete cylinder Sample
For compressive strength — Structural Concrete (buildings)
Meaning of CBS
Concrete Beam Sample
Use of Concrete Beam Sample
For flexural Strength — Concrete Pavement
What does concrete mixed of
Cement
Sand
Gravel
Water
Sampling of concrete
1-set of 3 (Cylinder/beam) every 75 cu.m or fraction thereof of each day of pouring.
Tools used in making and curing test specimens in the field
- Cylinder molds 150mm x 300mm (6 x 12inch)
- Mallet
- Rod 16mm (5/8inch) diameter 610 mm (24inch) long
Steps in molding specimens
- Scoop the sample using trowel and place it in a mixing pan
- Remix concrete to avoid segregation
- Pour in 3 equal layers
- 25 blows/layer using rod
- After each layer tap the outside of the mold lightly with 10 - 15 times with the mallet
- Penetrate the rod about 1” into the underlying layer
- After last layer been rodded, struck off with trowel and cover with glass or metal plate to prevent exaporation
Steps in curing
- Remove from mold after 24 hours
- Tests specimens shall be sent to the laboratory not more than 7 days prior to the time of test
- While in the laboratory the specimens shall be kept at laboratory temperature until 24 to 48 hours before testing
- Take samples from at least 3 parts of the load
- Use only non-absorptive molds
Fill mold in three equal layers, rod each layer 25 times with a spherical-nose rod - Let cylinder stand undisturbed from 12 to 24 hours, with tops covered at temperatures between 60 degrees and 80 degrees F (16 - 17 degrees C)
- Pack cylinders carefully in saw dust and ship to laboratory for testing
How many days for curing for CCS?
28 days
or
At least 21 days in site and 6 days curing in laboratory
or 27 days in site and 1 day in laboratory
Sizes of CCS and CBS
6” x 12” - CCS
6” x 6” x 21” - CBS
meaning of PCCP
Portland Cement Concrete Pavement
What item number is PCCP
item 311
Size of sample in flexure test specimens (beams)
Depth = 3 x maximum nominal size of aggregate
Width = depth, or may be wider by not more than half
Length = 3 x depth + 2 inches or more
6”x 6” x 21” CBS
How many set of cylinder samples for structural concrete for each day of concreting operations
3
How many set of beam samples for paving concrete shall be obtained for each day of concreting operations
3
A set shall represent __________ for each class of concrete
75 cu.m. or fraction thereof
How many days for curing for CBS?
14 days
Lowest moisture content at which the soil will flow upon the application of a very small shearing force. It gives a certain measure of the shearing resistance of a soil when mixed with water
Liquid Limit
The minimum moisture content at which the soil can be readily molded without breaking or crumbling
Plastic Limit
Sieve analysis of liquid limit and plastic limit
Soil passing #40 sieve
Moisture content Determination
%moisture content (w) = [(weight wet - dry)/dry] x 100
What is item 405
Structural Concrete
Composition of Concrete
Cement
Water
Chemical Admixture
Aggregates
Composition of Concrete by volume
7-14% Cement
15-20% water
66-78% Aggregate
Requirements of Concrete
- It should have the required strength
- It should be uniform, watertight and resistant to wear, weather and other destructive materials
- It should not shrink excessively on cooling or drying nor expand excessively on wetting
- It should be resistant to fire, chemicals or to abrasion
Will retain its quality indefinitely if it does not come in contact with moisture
Cement
Chemical admixtures as defined by AASHTO M 194
Type A - Accelerating
Type B - Retarding
Type C - Water reducing
Type D - Water reducing High Range
Type E - Water reducing and Accelerating
Type F - Water reducing and Retarding
Type G - Water reducing High range & Retarding
Constitute a large part of the concrete.
Aggregates
Utmost care in selection of aggregates must be of prime concern such as:
1.Good quality
2. Strength
3. Durability and
4. Freedom from injurious materials
Represent the major volume of concrete, about 70 %
Fine and coarse aggregates
The important role they serve as the principal ingredient is often overlooked because their cost is much less than that of cement
Aggregates
Physical properties of Concrete
- Workability
- Strength
- Durability
- Impermeability
Defined as the ease in placing concrete without segregation into the final position where it is allowed to harden
Workability of Concrete
Degree of workability is dependent on:
- The type of construction and the methods of handling and placing concrete
- Water function
- Grading and maximum size of aggregates
Measuring Workability
- No accurate method
- most commonly used method is the slump test
Capability of concrete to withstand loads
Strength of concrete
Principally dependent on the “water-cement ratio”
Strength of Concrete
Continues to increase with age as long as it is protected from drying
Strength of Concrete
To be able to withstand deterioration due to weathering action
Durability of concrete
After construction, it decrease with time due to physical, chemical, reaction and internal factors
Durability of concrete
Is a function of the “water-cement ratio”
Durability of concrete
Is an essential requirement of concrete exposed to the weather
Imperviousness
Factors affecting production of high quality concrete
- Quality of paste
- Quality of aggregates
- Proper Handling and Placing
- Proper Curing
What is item 405
Structural Concrete
This item consists of a furnishing, placing and finishing concrete in all structures except pavements
item 405
According to item 405, concrete shall consist of a mixture of what>
Portland Cement, FA, CA, Admixture (when specified) and water
Classes of concrete use in structures
Class A
Class B
Class C
Class P
Class Seal