PROPOSED TWO-STOREY JAIME HILARIO INTEGRATED SCHOOL - LA SALLE

DIVISION 32 -EXTERIOR IMPROVEMENTSSECTION 32 11 23 -Aggregate Base CourseJune 2013

Project:Proposed Two-Storey Jaime Hilario Integrated School - La SalleLocation : Banawang, Bagac, Bataan

DIVISION 32 -EXTERIOR IMPROVEMENTS

SECTION 32 11 23 -Aggregate Base Course

PART 1 GENERAL

1.01 SCOPE

a. The work shall consist of furnishing, spreading and compacting crush aggregate base material of crushed gravel, crushed stoned or crushed rock, constructed on a compacted earth sub-base, all in accordance with the specifications and Drawings.

b. Crushed aggregate base material shall be Class B as shown on the table.

c. Where crushed aggregate base is required to be placed on a subgrade where the surface levels of the resulting subgrade levels are outside the permitted tolerances shown in Table 1 below, leveling course of crushed aggregate base material shall be laid as shown on the Drawings. This work shall comply with the requirements of this specification.TABLE 1

TOLERANCES FOF SUBGRADE LEVEL AND

SUB-BASE

SUBGRADE

LEVELSUB-BASE

Permitted variation from

design THICKNESS

OF LAYER+10

mm--10

Permitted variation

from design LEVEL

OF SURFACE+20

-30

mm-10+5

Permitted SURFACE IRREGULARITY measured

by 3m straight-edgemm3020

Permitted variation

from design CROSSFALL

or CAMBER%0.50.2

Permitted variation

from design LONGITUDINAL GRADE over 25m length%0.10.1

1.02 UNIT PRICE MEASUREMENT AND PAYMENT

By the cubic meters.

PART 2 PRODUCTS

2.01 MATERIAL REQUIREMENTS

a. Aggregates

1. Material for crushed aggregate base course shall consist of crushed or partly crushed hard durable gravel stone or rock fragments. It shall be clean and free from organic matter, lumps of clay and other deleterious substances. The material shall be of such a nature that it can be compacted readily under watering and rolling to form a firm, stable base.

b. The material shall comply with the following grading and quality requirements.

1. The aggregates, when graded shall produce a smooth, evenly distributed curve within the limits for Class B.

Table 2

Sub-Base Material Grading

US Standard SievePercent Passing by Weight

mmAlternativeClass B

50(2)100

37.5(1-)80-100

25(1)60-100

19()55-85

4.75(No. 4)35 - 60

2.00(No. 10)25 - 50

0.425(No. 40)15 - 30

0.075No. 200)8 - 15

2. The coarse aggregate material retained on a 4.75mm (No. 4) sieve shall consist of material of which not less than 50% by weight shall be crushed particles, having a minimum of one fractured face.

3. The coarse aggregate retained on a 4.75mm (No. 4) sieve shall have a percentage of wear by the Los Angeles Abrasion Test (AASHTO T96) of not more than 40.

4. The material shall have a loss of less than 12 percent when subject to five cycles of the Sodium Sulphate. Soundness test according to AASHTO T104.

5. The sand equivalent determined according to AASHTO T176 shall not be less than 50, and

6. The material passing the 19m () sieve shall have a minimum soaked CBR-value of 80% tested according to ASTM D1883. The CBR-value shall be obtained at the maximum dry density determined according to AASHTO T180, Method D.

7. The portion of material passing the 0.425mm (No. 40) sieve shall have a Liquid Limit of not more than 25 and a Plasticity Index of not more than 6 as determined by AASHTO T89 and 90, respectively.

c. Filter

If filter in additional to that naturally present in the aggregate base material is necessary for meeting the grading requirements or otherwise it shall be uniformly blended with the base course material at the crushing plant or in a pugmill unless otherwise specified or approved. The material for such purpose shall be obtained from sources approved by the Engineer, shall be free from hard lumps and shall not contain more than 15 percent of material retained on the 4.75mm (No. 4 sieve).

PART 3 EXECUTION

3.01 CONSTRUCTION REQUIREMENTS

a. Placing

Crushed aggregate base shall be delivered to the site of the work as a uniform mixture. The placing of the material shall conform to the requirements of Section 32 11 16.16 entitled Granular Sub-base Course.

b. Compacting

Compacting shall conform in all respects to the requirements specified in Section 32 11 16.16 entitled Granular Sub-base Course.

c. Compaction Requirement

The compacted dry density of each layer of the compacted base shall not be less than 100 percent of the maximum dry density determined according to AASHTO T180, Method D. the field density shall be determined according to AASHTO T191.

d. Trial Sections

Trial sections shall conform in all respects to the requirements specified in Section 32 11 16.16 entitled Granular Sub-base.

e. Tolerances

The base shall be laid to the designated level and transverse slopes as shown on the Drawings. The allowable tolerances shall be in accordance with Table 1.

END OF SECTION 32 11 23Aggregate Base Course

32 11 23

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