Item No. 210

Flexible Base

210.1 Description

This item governs furnishing and placing a crushed stone base course for surfacing, pavement, or other base courses.  “Flexible Base" shall be constructed on an approved, prepared surface in one or more courses conforming to the typical sections and to the lines and grades, indicated on the Drawings or established by the Engineer or designated representative.

 

This specification is applicable for projects or work involving either inch-pound or SI units.  Within the text and accompanying tables, the inch-pound units are given preference followed by SI units shown within parentheses.

210.2  Submittals

The submittal requirements of this specification item may include:

A.   Source, gradation and TxDoT test results for the crushed limestone material,

B.   Notification that the crushed limestone is completed and ready for testing, and

C.  Field density test results for in-place compacted flexible base,

210.3  Material

A.   Mineral Aggregate

 

      The material shall be crushed argillaceous limestone meeting the requirements specified herein.  The material shall be from sources approved by the Utility and shall consist of durable crushed stone that has been screened to the required gradation.

 

      Flexible base materials shall be tested according to the following TxDoT standard test methods:

 

a) Preparation for Soil Constants and Sieve Analysis

Tex-101-E

b) Liquid Limit

Tex-104-E

c) Plastic Limit

Tex-105-E

d) Plasticity Index

Tex-106-E

e) Sieve Analysis

Tex-110-E

f)  Wet Ball Mill

Tex-116-E

g) Triaxial Test

Tex-117-E, Part II

 

 

Base material shall be stockpiled after crushing and may be then tested by the Utilities designated laboratory and approved by the Engineer or designated representative prior to being hauled to the Project.

 

The material shall be well graded and shall meet the following requirements:

 

Sieve Designation

Other Requirements

% Retained

 

US

SI

 

 

1 3/4"

45 mm

 

0

7/8"

22.4 mm

 

10-35

3/8"

9.5 mm

 

30-50

#4

4.75 mm

 

45-65

#40

425 mm

 

70-85

 

 

Maximum Plasticity Index

 

10

 

 

Maximum Wet Ball Mill

 

42

Maximum Increase in passing #40 (425 mm)

sieve from Wet Ball Mill Test

 

20

 

 

Minimum compressive strength when subjected to the triaxial test shall be 35 psi at 0 psi lateral pressure and 175 psi at 15 psi lateral pressure.

 

210.6   Measurement

When included in contract for separate payment, "Flexible Base" will be measured by the cubic yard, complete in place, as indicated in the Contract Documents.

210.7  Payment

Work performed and material furnished as prescribed by this item will be subsidiary to item no 510 “Pipe” unless included as a separate bid item in the contract. When included for payment, it will be paid for at the contract unit bid price for "Flexible Base".  The unit bid price shall include full compensation for all work specified herein, including the furnishing, hauling, placing and compacting of all materials; for rolling, proof rolling, recompacting and refinishing; for all water required; for retesting as necessary; for priming; and for all equipment, tools, labor and incidentals necessary to complete the Work.

 

Payment will be made under one of the following:

 

Pay Item:      Flexible Base                                                                             Per Cubic Yard.

 

END