2. RAW MATERIALS TESTS

In construction engineering projects, large quantity of different materials is used and it is necessary to test these materials according to certain set patterns within desirable frequency of testing in order that the quality of final product is maintained.

A.  Cement Tests

I.   Setting Time

The time between the water is added to cement till it starts losing its plasticity is called as initial setting time, The time between which water added to cement till it has come in hardened state is called final setting time, Setting time of cement used in concrete plays an important in fresh and hardened state of concrete, the test done by using Vigat test device this test is perform according to the ASTM C150, BS EN 196, BS EN 197

II.   Compressive Strength of Cement Cubes

It’s one of the Quality Control measures. It’s done to ensure that the product will perform as it should when it’s used in concrete. It’s performed according to the ASTM C150, BS EN 196, BS EN 197.

III.   Fineness Modulus Test

We know that the cement hydrates with the presence of water. When cement is mixed with the water, a thin layer is formed around the particle.

This layer grows bigger and makes cement particles to separate. Due to this, hydration process slows down. Therefore, the smaller particle will react much quicker than the larger particle. A particle with dia. 1µm will react entirely in one day, whereas the particle with dia. 10µm takes about one month. So, the particle size distribution is more critical in attaining the final strength of cement in allowable time.

Too much of smaller particles in cement results in quick setting, leaving no time for mixing, handling and placing. So to increase the setting time of cement, cement is grinded in a different range of particle sizes. The following proportions are usually maintained in Cement: About 10% of the cement of fine particles is smaller than 2 µm, 10% of wt of cement is made of particles larger than 50 µm, and only a few wt% is particles larger than 90 µm.

Fineness test is performed according to the ASTM C150, BS EN 196, BS EN 197

IV.   Loss on Ignition 

It’s a test used in inorganic analytical chemistry, particularly in the analysis of minerals. It consists of strongly heating (“igniting”) a sample of the material at a specified temperature, allowing volatile substances to escape, until its mass ceases to change. This may be done in air, or in some other reactive or inert atmosphere. This test is performed according to the ASTM C150, BS EN 196, BS EN 197

V.   Chemical Tests

The procedures used in the chemical analysis of Portland cement are described in this group of tests. (So₃, C₃A, MgO, Fe₂O₃, Al₂O₂, SiO₂); According to the ASTM C150, BS EN196, BS EN197.

B.  Aggregate Test

I.   Sieve Analysis of Aggregate

This test method is used primarily to determine the grading of materials proposed for use as aggregates or being used as aggregates. The results are used to determine compliance of the particle size distribution with applicable specification requirements and to provide necessary data for control of the production of various aggregate products and mixtures containing aggregates. and from this test result can be get Fineness Modulus which is important to concrete mix design. This test is preformed according to ASTM C136 or BS 812.

II.   Bulk Density

This test method is often used to determine bulk density values that are necessary for use for many methods of selecting proportions for concrete mixtures. this test is preformed according to ASTM C29 or BS 812

III.   Specific Gravity

It is the ratio of the weight of a given volume of aggregate to the weight of an equal volume of water. Water, at a temperature of 73.4°F (23°C) has a specific gravity of 1. Specific Gravity is important for several reasons. Some deleterious particles are lighter than the good aggregates. Tracking specific gravity can sometimes indicate a change of material or possible contamination. Differences in specific gravity may be used during production to separate the deleterious particles from the good using a heavy media liquid, the test done according with to ASTM C127 or BS 812.

IV.   Absorption

It’s the percent of water necessary to add to the aggregate to obtain saturated surface condition (SSD).

Absorption values are used to calculate the change in the weight of aggregate due to water absorbed in the pore spaces.  They are also used to calculate the amount of water that is absorbed by aggregates during Portland concrete mix preparation. ASTM C127 or BS 812.

C.  Water Tests

Quality of water for construction use is determined in the laboratory. It’s important because of its effect on chemical properties of concrete. This test is done according to ASTM C1602 or BS 1881.

Following are the tests required for quality of water for Concrete construction purpose:

1. PH Value Test
2. Chloride Test

• • Sulphate Test

1. Limits of Acidity Test
2. Limits of Alkalinity Test
3. Percentage of Solids

• • Suspended Matters
  • Organic and Inorganic Solids

3.  STEEL BAR AND PLATES TEST

A.  Tensile Test

Provide information on the strength and ductility of materials under axial tensile stresses. This information may be useful in comparisons of materials, alloy development, quality control, and design under certain circumstances.

Elongation is a strong function of volume of material participated in the deformation process (read, gage length) All standard test procedures recommend a preferable gauge length (or gage area) so that % elongation obtained can be compared across.

The test is performed according to the ASTM A615, BS 4449, Iraqi stands I.Q.S 2091

B.  Bending Test

Bend testing a material allows for the determination of that materials ductility, bend strength, fracture strength and resistance to fracture. These characteristics can be used to determine whether a material will fail under pressure. The test is performed according to ASTM A370

C.  Chemical Tests

These test methods for the chemical analysis of metals and alloys are primarily intended as referee methods to test such materials for compliance with compositional specifications, particularly those under the jurisdiction of ASTM Committees A01 on Steel, Stainless Steel, and Related Alloys and A04 on Iron Castings. It is assumed that all who use these test methods will be trained analysts capable of performing common laboratory procedures skillfully and safely. It is expected that work will be performed in a properly equipped laboratory under appropriate quality control practices such as those described in Guide E882.

The test is performed according to ASTM E350 – 18

4. ASPHALT TESTS

A.  Asphalt Mix Tests

I.   Asphalt Content

The proportion of asphalt in the mixture is critical and must be accurately determined in the laboratory and then precisely controlled on the job. The optimum asphalt content of a mix is highly dependent on aggregate characteristics such as gradation and absorptive. Aggregate gradation is directly related to optimum asphalt content. The test done by washing method (centrifugal) to find asphalt content and it done according to ASTM D6307 or BS 812.

II.   Asphalt Specific Gravity

The theoretical maximum specific gravities and densities of bituminous paving mixtures are fundamental properties whose values are influenced by the composition of the mixture in terms of types and amounts of aggregates and bituminous materials.

Maximum specific gravity is used (1) in the calculation of air voids in the compacted bituminous paving mixture, (2) in calculating the amount of bitumen absorbed by the aggregate, and (3) to provide target values for the compaction of paving mixtures, ASTM D2041 BS 812.

 III.   Marshall Test

The Marshall Stability and flow test provides the performance prediction measure for the Marshall mix design method. The stability portion of the test measures the maximum load supported by the test specimen at a loading rate of 50.8 mm/minute. Load is applied to the specimen till failure, and the maximum load is designated as stability. During the loading, an attached dial gauge measures the specimen’s plastic flow (deformation) due to the loading. The flow value is recorded in 0.25 mm (0.01 inch) increments at the same time when the maximum load is recorded. The important steps involved in marshal mix design are summarized next.  the test done according with ASTM D6927 and BS 812.

B.  Asphalt Compaction Ratio (Core Test)

Compaction is the process by which can be comparing between maximum density of asphalt mix and that density at field to find the quality of pavement. The volume of air in a hot asphalt mixture is reduced by using external forces to reorient the constituent aggregate particles into a more closely spaced arrangement. This reduction of air volume produces a corresponding increase in hot asphalt mix density. It’s typically expressed as “percent air voids”, It is done by getting cores from site (new paved areas) to lab to check it with standards procedure. The test done according with ASTM D3387 or BS 1377

C.  Asphalt Raw Materials Tests

I.   Tests of Aggregate

Aggregate plays important role in pavement construction. Aggregates influence, to a great extent, the load transfer capability of pavements. it is essential that they should be thoroughly tested before using for construction. Not only that aggregates should be strong and durable, they should also possess proper shape and size to make the pavement act monolithically.

II.   Gradation Test

The gradation and size is used to determine aggregate particle size distribution. Size distribution is perhaps the single most important aggregate quality associated with the control of Hot Asphalt mixtures. Aggregate gradation and size affect hot mix volumetric properties as well as mixture permeability and workability.

In a gradation and size analysis, a sample of dry aggregate of known weight is separated through a series of sieves with progressively smaller openings. Once separated, the weight of particles retained on each sieve is measured and compared to the total sample weight. Particle size distribution is then expressed as a percent retained by weight on each sieve size. Results are usually expressed in tabular or graphical format.

The standards of gradation and sieve analysis test are AASHTO T 27, ASTM D5444 and BS EN 12697

III.   Soundness Test

Soundness test is intended to study the resistance of aggregates to weathering action, by conducting accelerated weathering test cycles. The Porous aggregates subjected to freezing and thawing is likely to disintegrate prematurely. To ascertain the durability of such aggregates, they are subjected to an accelerated soundness test as specified with ASTM C88 or BS 812.

IV.   Shape Index Test

The particle shape of the aggregate mass is determined by the percentage of flaky and elongated particles in it. Aggregates which are flaky or elongated are detrimental to higher workability and stability of mixes.

The flakiness index is defined as the percentage by weight of aggregate particles whose least dimension is less than 0.6 times their mean size. Flakiness gauge is used for this test.

Test procedure had been standardized with ASTM D3398 and BS 812.

The elongation index of aggregate is defined as the percentage by weight of particles whose greatest dimension (length) is 1.8 times their mean dimension. This test is applicable to aggregates larger than 6.3 mm. Elongation gauge is used for this test. This test is also specified with ASTM D4791 or BS 812.

V.   Specific Gravity

It is the ratio of the weight of a given volume of aggregate to the weight of an equal volume of water. Water, at a temperature of 73.4°F (23°C) has a specific gravity of 1000 Kg/m³. Specific Gravity is important for several reasons. Some deleterious particles are lighter than the good aggregates. Tracking specific gravity can sometimes indicate a change of materials. The test done with ASTM C127, C128 and BS 812.

D.  BITUMEN TESTS

I.   Flash point Test

The fundamental reason for the requirement of flash point measurements is to assess the safety hazard of a liquid or semi-solid with regard to its flammability and then classifies the liquid into a group. The lower the flash point temperature, the greater the risk. This classification is then used to warn of a risk and to enable the correct precautions to be taken when using, storing or transporting the liquid. the test done according with ASTM D92 or BS 812.

II.   Penetration Test

The penetration test is used as a measure of consistency. Higher values of penetration indicate softer consistency, this test is performed according to ASTM D5/D5M & BS 812.

III.   Ductility Test

This test method provides one measure of tensile properties of asphalt materials and may be used to measure ductility for specification requirements. ASTM D113 BS 812.

IV.   Separation Tendency of Polymer

This test investigates the tendency of polymers to separate from the polymer modified bitumen (PMB). Using a special ovens, the samples are stored in a vertical position under heating at  163 ± 5 °C for 48 hours. At the end of the procedure, the top and bottom fractions of the sample are extracted and analyzed through additionnal tests such as softening point test. A significant difference between the two extracted fractions may indicated an incompatibility between the bitumen and the polymer.

This test is conducted in accordance with ASTM D7173

V.   Softening point test

Softening point denotes the temperature at which the bitumen attains a particular degree of softening under the specifications of test. The test is conducted by using Ring and Ball apparatus. In general, higher softening point indicates lower temperature susceptibility and is preferred in hot climates. This test is conducted in accordance with ASTM D36.

VI.   Specific gravity test

The specific gravity of bitumen is defined as the ratio of the mass of given volume of bitumen of known content to the mass of the equal volume of water at 27 C. The specific gravity of bitumen is measured using either pycnometer or preparing a cube specimen of bitumen in the semi-solid or solid state. This test is conducted in accordance with ASTM D70.

VII.   Viscosity Test

The viscosity of bitumen and tar in road construction practice is based on the test result obtained with orifice type viscometer. This test is carried Out to determine the viscosity of bitumen and tar which remain fluid under the specified temperature of the test. This test is conducted in accordance with ASTM D88.

VIII.   Float test

Certain range of bitumen consistencies cannot be measured by penetration test or viscosity test, the float test is used instead. . The apparatus consists of an aluminum float and a brass collar filled with bitumen to be tested. The specimen in the mould is cooled to a temperature of 5 ⁰C and screwed in to float. The total test assembly is floated in the water bath at 50 ⁰C and the time required for water to pass its way through the specimen plug is noted in seconds and is expressed as the float value. This test is conducted in accordance with ASTM D139.

IX.   Water content test

The water in a bitumen is determined by mixing known weight of specimen in a pure petroleum distillate free from water. The mixture is then heated and distiled, the weight of the water condensed and collected is expressed as the percentage by weight of the original sample. In general, the allowable maximum water content should not be more than 0.2% by weight. This test is conducted in accordance with ASTM D 1461

X.   Loss on heating test

When the bitumen is heated it loses the volatility and gets hardened. To conduct this test, about 50gm of the sample is weighed and heated to a temperature of 163 ⁰C for 5 hours in a specified oven designed for this test. The sample specimen is weighed again after the heating period and loss in weight is expressed as the percentage by weight of the original sample. Note: Bitumen used in pavement mixes should not indicate more than 1% loss in weight, but for bitumen having penetration values 150-200 up to 2% loss in weight is allowed.This test is conducted in accordance with ASTM D6

6. PILE TESTS

A.  STATIC AXIAL COMPRESSIVE LOAD TEST

Test shall be conducted according to ASTM D1143 Standard Test Method for Piles under Static Axial Compressive Load.

The static axial capacity of piles typically changes as time elapses after pile installation, possibly increasing (setup) or decreasing (relaxation), depending on the soil or rock properties and the pore water pressure and soil structure disturbance induced by installation. This behavior may affect both driven piles and cast-in-place piles.

The test method described in the standard measure the axial deflection of a vertical or inclined deep foundation when loaded in static axial compression. These methods apply to all deep foundations (Piles), That function in a manner similar to driven piles or cast-in-place piles, regardless of their method of installation, and may be used for testing single pile or piles group.

B.  STATIC AXIAL TENSILE LOAD TEST

Test shall be conducted according to ASTM D3689 Standard Test Method for Piles under Static Axial Tensile Load.

Field tests provide the most reliable relationship between the axial load applied to a deep foundation and the resulting axial movement. Test results may also provide information used to assess the distribution of side shear resistance along the pile shaft and the long-term load-deflection behavior. A foundation designer may evaluate the test results to determine if, after applying an appropriate factor of safety, the pile or pile group has an ultimate static capacity and a deflection at service load satisfactory to support a specific foundation. When performed as part of a multiple-pile test program, the designer may also use the results to assess the viability of different piling types and the variability of the test site.

The test method described in the standard measure the axial deflection of a vertical or inclined deep foundation when loaded in static axial Tension. These methods apply to all deep foundations (Piles), That function in a manner similar to driven piles or cast-in-place piles, regardless of their method of installation, and may be used for testing single pile or piles group.

C.  STATIC LATERAL LOAD TEST

Test shall be conducted according to ASTM D3966 Standard Test Method for Piles under Static Axial Tensile Load.

This test method described in this standard measure the lateral deflection of vertical or inclined deep foundations when subjected to lateral loading. It is applicable to all deep foundation units regardless of their size or method. The actual lateral load capacity of the pile-soil system can test be determined by lateral testing. Such testing measures the response of the pile-soil system to lateral loads and may provide data for research and development, engineering design, quality control, and acceptance or rejection under specifications. Under the iterative elastic method of analysis that considers the nonlinear response of the soil. Lateral testing combined with proper instrumentation can be used to determine soil properties necessary for the structural design of the pile to resist the lateral load to be applied. Reaction system shall also be monitored for movement.

D.  DYNAMIC TEST

Test shall be conducted according to ASTM D4945 Standard Test Method for Standard Test Method for high strain dynamic testing of piles.

This test consists of estimating soil resistance and its distribution from force and velocity measurement obtained near the top of a foundation.

This dynamic test method covers the procedure for applying an axial impact force with a pile driving hammer or a large drop weight that will cause a relatively high strain at the top of an individual vertical or inclined deep foundation unit, and for measuring the subsequent force and velocity response of that deep foundation unit. High-strain dynamic testing applies to any deep foundation unit, also referred to herein as a “pile,” which functions in a manner similar to a driven pile or a cast-in-place pile regardless of the method of installation, and which conforms with the requirements of this test method.

E.   INTEGRITY TEST

Test shall be conducted according to ASM D5882 “Low Strain Impact Integrity Testing of Deep Foundations”

This test method covers the procedure for determining the integrity of individual vertical or inclined piles by measuring and analyzing the velocity (required) and force (optional) response of the pile induced by an (hand held hammer or other similar type) impact device usually applied axially and perpendicularly to the pile head surface. This test method is applicable to long structural elements that function in a manner similar to any deep foundation units (such as driven piles, augured piles, or drilled shafts), regardless of their method of installation provided that they are receptive to low strain impact testing.

The tests measures, Pile length, or depth to anomalies Pile head stiffness Pile shaft mobility-which is dependent on pile section and concrete properties. The software, also produces computer simulation and impedance profile of the test result to analyze in detail any intermediate pile shaft response.