2.) Sections 4.1 and 4.1.1 -- to be disregarded as they are solely intended for HMA.
3.) Section 4.2 — replaced in its entirety to read “Test Specimens — specimen length and
width must match Figure | (cutting template), and specimen height must be 0.50 in.
Make and cure the micro-surfacing overlay test specimens using similar methods and
resulting in similar mixture composition and mix consistency as done for the TB 100
(Wet Track Abrasion) and TB 147 (Loaded Wheel Test) specimens.
4.) Sections 5.1 and 5.2.3 — to be disregarded as they are solely intended for HMA.
5.) Section 5.3.1 — only the first sentence shall apply (“Mount and secure the base plates to
the mounting jig.”)
6.) Sections 5.4 and 5.7.1 — change 77 degrees F to 41 degrees F.
7.) Section 5.7.2 — change 93% to 90% and add “specimens are required to meet 100 cycles
minimum before reaching the 90% reduction.”
In the event that new performance testing standards are developed to supersede the modified
TxDOT Overlay Test standards outlined above, such new standards shall be submitted and
approved by the Engineer.
Specifications
The Engineer shall approve the design mix and all micro-surfacing materials and methods prior
to use. The component materials shall be within the following limits.
Residual Asphalt 5% to 9% by dry weight of aggregate
Mineral Additive 0.5% to 3% by dry weight of aggregate
Polymer Modifier As required to provide specified properties
and Field Control
Additives
Water As required to produce consistency
Fibers 0.05% to 0.25% by dry weight of aggregate as required to meet the
performance requirements of the TxDOT Overlay Test (Tex-248-
F) as described above
