Attachment 2 - Special Provisions~8.pdf

Pearl St. Pedestrian Bridge Rehabilitation I&M Canal State Trail (Marseilles)

IDNR# 2-22-023

Special Provisions

REMOVE AND REPLACE ANCHOR BOLTS

Description. This work shall consist of the removal and disposal of existing steel anchor bolts, nuts and washers, and the installation of new steel anchor bolts, nuts and washers in accordance with the materials, dimensions and details shown on the Plans. Work shall be performed in accordance with the applicable portions of Sections 501 and 505 of the Standard specifications.

Drawings. Prior to ordering of materials, shop drawings shall be submitted to the Engineer for review and approval in accordance with Article 505.03 of the Standard Specifications.

Basis of Payment. The cost of this work will be included in the contract lump sum price for the project.

REMOVAL OF EXISTING TIMBER MATERIAL

Description. This work shall consist of the total removal and disposal of existing timber material and its associated hardware. Work shall be performed in accordance with the applicable portions of Sections 501 and 507 of the Standard specifications. The contractor shall exercise care when removing timber members attached to the existing concrete structure, so that the concrete or masonry structures to remain are undamaged. Any damage caused during timber removal shall be repaired at the contractor’s expense.

POLYMER MODIFIED PORTAND CEMENT MORTAR

Description. This work shall consist of furnishing all materials and labor required to remove and dispose of deteriorated concrete, and replace it with a polymer modified portland cement mortar at those locations shown on the plans or designated by the Engineer. The use of this mortar is intended to repair spalls between 3/8 in. and 2 in. deep on horizontal, vertical, and overhead surfaces.

Materials. Materials shall be according to the following.

Item Article/Section

(a) Polymer Modified Portland Cement Concrete (Note 1)

(b) Water 1002

(c) Cotton Mats 1022.02

(d) Protective Coat 1023

(e) Epoxy (Note 2) 1025

IDNR# 2-22-023

Note 1. Polymer modified portland cement mortar shall be a packaged product consisting of portland cement, fine aggregate, and a polymer modifier.

(1) The portland cement shall be according to Article 1001.01

(2) The fine aggregate shall be an FA 1 or FA 2, according to Articles 1003.01 and 1003.02.

(3) The polymer modified portland cement mortar shall meet the following physical requirements:

a. The mortar shall be a workable mix capable of bonding and holding its own plastic weight, when mixed and placed according to manufacturer instructions, on vertical and overhead surfaces. The testing shall be according to Illinois Laboratory Test Procedure “Evaluation of Vertical and Overhead Adhesion for Polymer Modified Portland Cement Mortar”.

b. The mortar shall have a minimum compressive strength of 1,500 psi (10,300 kPa) at 24 hours, 3,000 psi (20,700 kPa) at 3 days, and 5,000 psi (34,500 kPa) at 28 days;

according to ASTM C 109.

c. The mortar shall have a minimum bond strength of 2,000 psi (13,800 kPa) at 28 days, according to the Illinois Laboratory Test Procedure “Evaluation of Bond Strength by Slant Shear”.

d. The mortar shall have a water soluble chloride ion content of less than 0.40 lb/cu yd (0.24 kg/cu m). The test shall be performed according to ASTM C 1218, and the mortar shall have an age of 28 to 42 days at the time of test. The ASTM C 1218 test shall be performed by an independent lab a minimum of once every two years, and the test results shall be provided to the Department.

The Department will maintain an Approved List of Polymer Modified Portland Cement Mortar.

Note 2. In addition ASTM C 881, Type IV, Grade 2 or 3, Class A, B, or C may be used.

Equipment. Equipment shall be according to Article 503.03 and the following:

(a) Chipping Hammer – The chipping hammer for removing concrete shall be a light-duty pneumatic or electric tool with a 15 lb class or less.

(b) Blast Cleaning Equipment – Blast Cleaning equipment for concrete surface preparation shall be the abrasive type, and the equipment shall have oil traps.

Concrete Removal. The Contractor shall provide ladders or other appropriate equipment for the Engineer to mark the removal areas. Repair configurations will be kept simple, and squared corners will be preferred. The repair perimeter shall be sawed a depth of 3/8 in. (10 mm) or less, as required to avoid cutting any reinforcement that may be present. If the concrete is broken or

IDNR# 2-22-023

removed beyond the limits of the initial saw cut, the new repair perimeter shall be recut. The areas to be repaired shall have all loose, unsound concrete removed completely by the use of chipping hammers or other methods approved by the Engineer.

The repair depth shall be a minimum of 3/8 in. and a maximum of 2 in. The substrate profile shall be ± 1/16 in. The perimeter of the repair area shall have a vertical face.

The Contractor shall have a maximum of 7 calendar days to complete each repair location with mortar, once concrete removal has started for the repair.

Surface Preparation. Prior to placing the mortar, the Contractor shall prepare the repair area and exposed reinforcement by blast cleaning. The blast cleaning shall provide a surface that is free of oil, dirt, and loose material.

The repair area and perimeter vertical face shall have a rough surface. Care shall be taken to ensure the perimeter sawcut is roughened. Just prior to mortar placement, saturate the repair area with water to a saturated surface-dry condition. Any standing water shall be removed.

Mortar placement shall be done within 3 calendar days of the surface preparation or the repair area shall be prepared again.

Reinforcement. Exposure of existing reinforcement bars is not anticipated as part of this work.

If reinforcement bars are encountered during removal, repair work shall be stopped and the Department or Engineer of Record shall be contacted for further instructions.

Placement. Mix and place the polymer modified portland cement mortar according to the manufacturer’s instructions. The mortar shall be placed and finished to the contours of the member, as originally constructed.

The mortar shall not be placed when the air temperature is below 45 °F and falling or below 40 °F. Mortar shall not be placed when the air temperature is greater than 90 °F. The mortar shall have a minimum temperature of 50 °F and a maximum temperature of 90 °F. The mortar shall not be applied during periods of rain unless protective covers or enclosures are installed. The mortar shall not be applied when frost is present on the surface of the repair area, or the surface temperature of the repair area is less than 40 °F.

Curing. Cotton mats shall be applied, according to Article 1020.13(a)(5), to the exposed layer of mortar within 10 minutes after finishing, and wet curing shall begin immediately. Curing shall be for a minimum of 3 days. If temperatures below 45° F are forecast during the curing period, protection methods shall be used. Protection Method I according to Article 1020.13(d)(1), or Protection Method II according to Article 1020.13(d)(2) shall be used during the curing period.

IDNR# 2-22-023

Inspection of Completed Work. The Contractor shall provide ladders or other appropriate equipment for the Engineer to inspect the repaired areas. After curing but no sooner than 28 days after placement of the mortar, the repair shall be examined for conformance with original dimensions, cracks, and delaminations. Sounding for delaminations will be done with a hammer or by other methods determined by the Engineer.

The repaired area shall be removed and replaced, as determined by the Engineer, for nonconformance with original dimensions, surface cracks greater than 0.01 in. in width, map cracking with a crack spacing in any direction of 18 in. or less, or delaminations.

If the repair is allowed to remain in place, cracks 0.01 in. or less shall be repaired with epoxy according to Section 590. For cracks less than 0.007 in., the epoxy may be applied to the surface of the crack.