610.02 Materials.
Additional pins, regardless of location, shall be installed as necessary to prevent any slippage of the geo textile filter. Each securing pin shall be pushed through the filter until the washer bears against the filter and secures it firmly to the foundation. The filter shall be protected at all times during construction from contamination by surface runoff and any filter so contaminated shall be removed and replaced with uncontaminated filter. Any damage to the filter during its installation or during placement of riprap shall be replaced by the Contractor. The work shall be scheduled so that 30 days does not ex pire between placement of the filter and the covering of the filter with the graded aggregate. Aggregate shall not be dropped on the filter from a height greater than 1 foot {300 mm}. Greater drop heights will be permitted if the Contractor provides a cush ioning layer of sand on top of the filter before dumping of stone. The combination of drop height for stone and sand cushion layer thickness to be approved shall be demonstrated to not puncture or damage the filter. No measurement or separate payment shall be made for a sand cushion layer placed for the purpose of allowing an increased drop height of stones. Any damage to the geotextile filter during placement of aggregate shall be corrected prior to proceeding with the work.
c.Placement of Aggregate . The method of placement of the aggregate shall be at the option of the Contractor provided it produces uniform coverage and depth without damaging the geotextile filter, if present. Any damage to the filter shall be cause for ordering the aggregate cleaned from the damaged area and the repair of the filter by an additional layer of filter covering the damaged area overlapping at least 3 feet {1 m} onto undamaged filter and securing the patch with adequate securing pins. If uniformity of coverage is not obtaine d by the method of placement, such shall be corrected in a manner satisfactory to the Engineer. No compaction of the aggregate blanket is required.
609.04 Method of Measurement.
Accepted aggregate slope protection and geotextile filter for aggregate slope protection, if applicable, will each be measured in square yards {square meters}, complete in place, computed from actual measurements taken along the top surface of the treated area to the nearest 0.1 square yard {0.1 m²}.
609.05 Basis of Payment.
a.Unit Price Coverage . The accepted Aggregate Slope Protection and geotextile filter for aggregate slope protection, measured as noted above, will each be paid for at the contract unit price bid per square yard {square meter}. Said unit price bi d shall be full compensation for the item complete in place and includes the furnishing of all materials, the preparation of the slope (excavation, backfill, compacting slope, disposal of surplus material), placement of materials and for all equipment, too ls, labor, and incidentals necessary to complete the work.
b.Payment will be made under Item No .: 609-A Aggregate Slope Protection - per square yard {square meter} 609-B Geotextile Filter for Aggregate Slope Protection - per square yard {square meter}
610.01 Description.
This Section shall cover the work of furnishing and constructing the several classes or types of r iprap, each of which shall consist of a protective course of stone or other approved materials on embankment slopes, in channels and ditches, wave protection for causeways and shoreline roadway embankments, bridge piers and abutments, or other work as shown on the plans or directed, with or without a geotextile filter, all in accordance with these specifications and in conformity with the lines, and grades note d in the plan details.
610.02 Materials.
If a geotextile filter is required, it shall meet the requirements of AASHTO M 288 for Permanent Erosion Control Geotextile, Class 1, and Section 810 of these specifications. All other materials shall
610.03 Construction Requirements.
conform to the requirements of Division 800, Materials. Specific reference is made to Section 814, Riprap Materials. The geotextile shall be selected from List II -3, of the Department's manual titled "Materials, Sources, and Devices With Special Acceptance Requirements" . Information concerning this list is given in Subarticle 106.01(f) and ALDOT -355. In locations where maintaining the clear zone is a consideration, a traversable tied concrete block mat may be used in lieu of riprap. Tied concrete block mat shall be selec ted from the Department’s Miscellaneous Approved Products List/LIST II -24 “TEMPORARY AND PERMANENT EROSION AND SEDIMENT CONTROL PRODUCTS.” All mats must be installed with the manufacturer’s recommended underlayments/backings for site specific conditions. A ll mats and accompanying underlayments/backings shall have a minimum shear stress capacity of 10 pounds per square foot as tested per ASTM D6460. Prior to installation, the contractor shall submit documentation from the manufacturer, indicating the product meets the requirements for approval by the Engineer .
610.03 Construction Requirements.
a.General . All slopes to be treated with riprap shall be trimmed to the lines and grades indicated by the plans or directed; loose material shall be compacted by meth ods approved by the Engineer or removed. Slopes which require a geotextile blanket under the riprap shall, in addition to the above, be prepared as noted in Subarticle (b) below. Placement of any riprap on a filter blanket shall be by such means that will not damage or destroy the blanket. Any damage to the blanket shall be repaired without additional compensation. Unless otherwise authorized or directed by the Engineer, riprap protection for bridge ends shall be placed immediately following the grading ope rations. The bridge Contractor shall protect any slope protection material in place during the bridge construction and shall be responsible for any damage due to negligence on the part of his operations. If directed by the Engineer or shown by plan details , all outer edges and the top of riprap where the riprap terminates shall be formed so that the surface of the riprap will be embedded and even with the surface of the ground and/or slope. All riprap construction shall begin at the bottom of the slope and progress upward.
b.Filter Blanket.
1.General . Unless otherwise specified by the plans or ordered in writing, the Contractor may select one of the filter blanket materials provided in Article 814.03 for construction of the filter blanket except that a geotextile blanket will not be allowed for soils with 85% by weight {mass} passing the #200 {75 µm} sieve. If an aggregate blanket is used, the blanket shall be constructed using the designated material to a minimum thickness of 6 inches {150 mm}, unless o therwise shown by the plans, all in accordance with the provisions noted in this Subarticle and the plan details. If a geotextile filter is used, it shall conform with Article 610.02 of this Section.
2.Foundation Preparation . Areas on which filter blanket s are to be placed shall be uniformly trimmed and dressed to conform to cross sections shown by the plans within an allowable tolerance of plus or minus 3 inches {75 mm} from the theoretical slope lines and grades.
3.Placement .
a.Aggregate Blankets (Grav el or Crushed Stone). Filter blanket material shall be spread uniformly on the prepared base, in a satisfactory manner, to a thickness of not less than 1/2 of an inch {10 mm} from that specified and to neat lines as indicated on the plans. Placing or spreading of material by methods which will tend to segregate particle sizes within the filter layer will not be permitted. Any damage to the surfaces of the filter blanket foundation during the placing of the filter blanket shall be repaired before proceeding with the work. Compaction of the filter material will not be required, but shall be finished to present a reasonably even surface free from mounds, depressions, or windrows.
b.Geotextile Filter. Exposure of geotextiles to the elements between lay down and cover shall be a maximum of 14 days to minimize damage potential.
610.03 Construction Requ irements.
The geotextile shall be placed and anchored on a smooth graded surface approved by the Engineer. The geotextile shall be placed in such a manner that placement of the overlying materials will not excessively stretch or tear the filter. Anchoring of the terminal ends of the geotextile shall be accomplished through the use of key trenches or aprons at the crest and toe of the slope. In certain applications, 18 inch {450 mm} long anchoring pins , placed on 2 to 6 foot {1 to 2 m} centers, depending on the slope of the covered area, should be used to expedite construction. Successive geotextile sheets shall be overlapped in such a manner that the upstream sheet is placed over the downstream sheet a nd/or upslope over downslope. In underwater applications, the geotextile and required thickness of backfill material shall be placed the same day. The backfill placement shall begin at the toe and proceed up the slope. Riprap and heavy stone filling shall not be dropped onto the geotextile from the height of more than 1 foot {300 mm}. Slope protection and smaller sizes of stone filling shall not be dropped onto the geotextile from a height exceeding 3 feet {1 m}. Any geotextile damaged during placement shal l be replaced as directed by the Engineer at the Contractor's expense. The geotextile shall be joined by either sewing or overlapping. All seams shall be subject to the approval of the Engineer. Overlapped seams shall have a minimum overlap of 12 inches {3 00 mm} except where placed underwater where the overlap shall be a minimum of 3 feet {1 m}. A geotextile patch shall be placed over the damaged area and extend 3 feet {1 m} beyond the perimeter of the tear or damage.
c.Stone Riprap .
1.General . Unless otherwise shown by the plan details or directed, stone riprap shall not be placed on slopes steeper than the natural angle of repose of the riprap material. Placement of stones may, unless otherwise noted in this Subarticle, be placed by methods and equipme nt approved by the Engineer suitable for the purpose of placing the riprap in accordance with the requirements for the class riprap involved without damaging any existing facility or construction feature.
2.Class 1. Class 1 riprap is essentially designed for hand placement and use with minimal water currents. Stones shall be laid with close broken joints and resting on the embankment slope. The stones shall be of such shape and shall be so laid as to produce a single layer of stone of the thickness shown on the plans, measured perpendicular to the slope. The bottom course shall be laid in a trench excavated to such depth below the toe of the slope that all parts of the bottom course will be 3 feet {1 m} below the toe. Trenching will not be required where th e toe of the slope is below water level. The back of the trench shall be on the same slope as the fill. The laying of the courses shall progress upward, the larger stones being placed in the lower courses. The individual pieces of stone in each horizontal course shall be laid so that they will break joints with the stones in the course below the tops sloped to drain away from embankment. Open joints shall be filled with spalls, or small stones in such manner that all stones are tightly wedged or keyed. The finished surface shall present a reasonably uniform appearance and shall not vary more than 6 inches {150 mm} from the average surface. The finished surface at the ends of the riprap shall be flush with the adjacent earth fill surface.
3.Class 2 and 3. Class 2 and 3 riprap is designed for use in areas with minimal to medium water currents and wave action. The stones shall be placed in such a manner as to produce a reasonably well graded mass of rock with the minimum practical percentage of voids. The ripra p shall be constructed to the lines, grades and thickness shown by the plans or directed within a tolerance of plus 15 inches {375 mm} or minus 3 inches {75 mm} from the designated finish surface of the riprap, except that either extreme of such tolerance shall be reached as a uniform rate over an area greater than 200 square feet {19 m²}. Riprap shall be placed in its full course thickness in one operation and in such a manner as to avoid displacing the filter blanket material, where filter blanket is requ ired. The larger stones shall be well distributed and the entire mass of stones in their final position shall conform to a reasonable uniform gradation. The finished riprap shall be free from objectionable pockets of small stones and clusters of larger sto nes. Placing riprap by dumping into chutes or by other methods likely to cause segregation of sizes will not be permitted. The desired distribution of the various sizes of stones throughout the mass shall be obtained by selective loading of the material at the source, by controlled dumping of successive loads during final placing, or by other methods of placement which will produce
610.04 Method of Measurement.
the specified results. Rearranging of individual stones by mechanical equipment, or by hand, will be required to the extent nec essary to obtain a reasonably well graded distribution of stone as specified above.
4.Class 4 and 5. Class 4 and 5 riprap is designed for use in medium to high water currents and wave actions for the protection of bridge piers and abutments, and protectio n of channel slopes. Stones may be placed without strict gradation controls provided sufficient small sizes are included to choke the larger stones. Dumping of the stones will be allowed; however, mechanical equipment to dress the material to a reasonable uniform slope will be required. Stones deposited contrary to directions will be considered wasted and will not be paid for.
d.Concrete Sacked Riprap . Immediately following mixing, as noted in Article 814.02, the mixture shall be placed in the bags, tied (so that when laid in position they will flatten out and give a thickness of not less than 6 inches {150 mm} and placed flat on the area designated. Bags shall be rammed against each other to form closed joints, with tied ends of sacks all laid in the same direction. When required to be placed under water, special care shall be taken to see that bags are closely jointed to give the same tight joints as required on dry slopes. After the riprap is placed, it shall be sprinkled with water as directed and kept damp for not less than three days. No Concrete Sacked Riprap shall be mixed in freezing weather.
e.Tied Concrete Block Mat. Tied concrete block mat shall be placed according to the manufacturer’s recommendations.
f.Maintenance . The Contractor shal l maintain all riprap until the contract is accepted, and shall replace, without additional compensation, any damaged or lost riprap.
610.04 Method of Measurement.
Loose Riprap of the class designated by the plans or proposal will be measured in square yar ds {square meters}, computed from measurements taken parallel to the surface of the riprap or in tons {metric tons} as specified in Subarticle 109.0l(h), whichever is specified by the plans or proposal. Concrete Sacked Riprap , Filter Blanket , and Tied Conc rete Block Mat will be measured in square yards {square meters} computed from measurements taken parallel to the outer surface of the riprap or the filter blanket, whichever is applicable.
610.05 Basis of Payment.
a.Unit Price Coverage . The contract unit price for Loose Riprap, Concrete Sacked Riprap , Filter Blanket , and Tied Concrete Block Mat shall be full compensation for furnishing and hauling all materials, preparation of the placement area, placing materials and for all equipment, tools, labor a nd incidentals necessary to complete these items of work. The preparation of the area for the placement of riprap and tied concrete block mat includes excavation, dressing the placement area and surrounding area, and the disposal of any excess excavated ma terial. Payment for this preparation shall be included in the contract unit price for the riprap unless otherwise noted on the plans.
b.Payment will be made under Item No .: 610-A Loose Riprap, Class ____ , ____ inches {mm} Thick - per square yard {squar e meter} 610-B Concrete Sacked Riprap - per square yard {square meter} 610-C Loose Riprap, Class ____ - per ton {metric ton} 610-D Filter Blanket, * - per square yard {square meter} 610-E Tied Concrete Block Mat – per square yard {square meter} * If a specific type of blanket is required, so designate (aggregate or geotextile).
612.03 Construction Requirements.
SECTION 611 MORTAR FOR MASONRY
611.01 Description.
This Section shall cover the work of furnishing mortar made in accordance with these specificat ions, for the various classes and kinds of masonry when its use is required.
611.02 Materials.
Materials shall conform to the provisions of Division 800, Materials. Specific reference is made to the following: Masonry Cement Article 815.06 Sand Article 802.03 Water Article 807.01 Hydrated Lime Section 805
611.03 Construction Requirements.
The mortar shall be composed of one part of cement and two parts of sand by volume, on basis of dry sand, and sufficient water to make a mortar of such consistency that it can be easily handled and spread with a trowel. If directed, hydrated lime, not to exceed 15 percent of cement by weight {mass}, shall be added, except that if masonry cement is used hydrated lime will not be required. Mortar shall be mixed only in quantities required for immediate use. Unless an approved mortar mixing machine is used, the sand and cement shall be mixed dry in a watertight box until the mixture assumes a uniform color, after which water shall be added as the mixing continues until the mortar attains the proper consistency. Mortar which is not used within 45 minutes after water has been added shall be wasted. Retempering of mortar will not be permitted.
611.04 Method of Measurement.
No measurement will be made for mortar for m asonry.
611.05 Basis of Payment.
Payment for mortar for masonry shall be included in unit prices of pay items for various kinds of masonry, and no direct payment will be made for mortar. SECTION 612 RUBBLE MASONRY
612.01 Description.
This Section shall cover the work of furnishing and constructing Rubble Masonry consisting of approved stones laid in mortar as a means of constructing structures or parts of structures in accordance with these specifications to the lines and dimensio ns shown on the plans or designated. Rubble Masonry as herein specified shall include the Types commonly known as Coursed Rubble, Uncoursed Rubble, and Rustic Rubble.
612.02 Materials.
Materials shall conform to the provisions of Division 800, Materials. S pecific reference is made to Type I and Type III, Masonry Stone, Subarticles 812.01(a) and (c), respectively. Mortar shall meet the requirements of Section 611, Mortar for Masonry.
612.03 Construction Requirements.
a.Shaping Stone .
1.Coursed and Uncours ed Masonry Stone . The stones shall be roughly squared on joints, beds and faces. All shaping or dressing of stone shall be done before the stone is laid and no dressing or hammering which will loosen the stone will be permitted after it is placed.
2.Rusti c Masonry Stone . Only shaping required will be that to eliminate sharp points and projections.
Source: Alabama Standard Specifications for Highway Construction, 2022 Edition. Pages 488–491 of 934.