ITEM 520 - HYDROSEEDING

520.1 Description

This Item shall consist of furnishing grass seeds mixed with an airtrol geobinder, cellulose fiber mulch, cocopeat and fertilizer to form into a consistent and, homogenous slurry and then sprayed evenly on the ground in accordance with this specification and in conformity with the lines, grades and dimensions shown on the plans or as established by the Engineer.

520.2 Material Requirements

520.2.1 Grass Seeds

The seeds to: be used for vegetative cover shall be the approved seed varieties that is tested to withstand harsh weather conditions, characteristically aggressive, perennial, tropical, produce both runners and thizomes, deep-rooted, will rapidly colonize bare ground and form a dense mat of vegetation ground cover. When established will form an umbrella surface cover to dissipate rain drops impact. Environmental friendly and low maintenance.

Permanent Ground Cover Grass Seed Temporary Grass Nursing Seed Seed Purity Germination Adaptability

Centrosa 50% Calopogonium 50% - 80 to 100kg/ha. White Millet - 30 kg/ha. 85% 80 – 90% Average Tropical

520.2.2 Geobinder

Airtrol geobinder is a low cost cementitious binder, when mixed with water and mulch, sets in a predictable way to form an erosion resistant crust. The application rate for Geobinder Airtrol should be 1,500 kg/ha.

520.2.3 Cellulose Fiber Mulch

It is manufactured and processed from recycled paper.

Moisture Content Organic Matter Water Holding Capacity pH Level Mulching Rate

15-20% 99.5% 100 grams OW will hold 1,000 grams of water 5.5 to 6.0% Dry Weight (OW) of water 1850 kg/hectare

520.2.4 Cocopeat

By-product of coco fiber consisting coco fiber and dust sieved in 5 mm mesh.

520.2.5 Fertilizer

Chemical/Grade/Organic Fertilizer locally produced and must be both environmental friendly and non-toxic.

520.3 Construction Requirements

Hydroseeding shall be used on critical cut slopes and bare clay surfaces to prevent soil erosion.

1. Site Preparation


1. Ground surface and cut slopes shall be graded and sloped to the approved design and obstructions snail be removed so the mixed materials are sprayed evenly forming a blanket cover to the soil surface.


2. Soil surface shall be wetted with water at least for one hour prior to application of hydroseeding.


2. Seeding


1. Use the cellulose mulch material mix with, a tackifier which will act as binder.
   
2. Mix the cellulose fiber mulch, together with the grass seeds, fertilizer and water in the tank of a hydroseeding machine to form into a consistent and homogenous slurry and then hydraulically sprayed to the ground.


3. Spray the cellulose fiber mulch together with the fertilizer grass seeds which will act as an absorbent mat, holding enough moisture to allow proper germination of the grass seeds and at the same time forming a tenacious blanket cover to the soil surface even before the grass seeds germination to prevent soil erosion.


4. Let the cementitious geobinder form a permeable crust on the soil surface which will control water, soil and wind erosion.


5. Use the geobinder which is a non-toxic cementitious binder that safely hold the grass seeds uniformly in place prevents surface erosion and water evaporation in the soil. The cellulose fiber mulch, which is biodegradable, will in time revert back to organic matter and assist in the vigorous establishment of the grass ground cover.


6. Wait for the temporary grass seeds to germinate in forty eight (48) hours after spraying and in which the planting bed of the embankment shall already be 100% stabilized even before the establishment of the permanent ground cover grass seeds.

520.4 Maintenance

The entire hydroseeded area shall be grown-in and maintained for sixty (60) to ninety (90) calendar days from date of the hydroseeding completion. Client shall provide continuous watering after the grown-in period. All areas applied with hydroseeding shall be trimmed.

520.5 Equipment to Be Used (1-5 Hectare Area)

1 Unit - Hydroseeding Machine

1 Unit -Truck for Materials Support

1 Lot - Various Hydroseeding Hoses and Accessories 1 Unit -Water Tank for Watering Machine

520.6 Delivery, Storage and Handling

Store the seed in such a manner that it will be prevented from wetting and deterioration of the seed.

520.7 Method of Measurement

Hydroseeding shall be measured by the square meter and the quantity to be measured for payment shall be the actual area in square meters of area on which the hydroseeding has been placed in accordance with this specification and within the limits of construction as designated on the Plans or as ordered by the Engineer.

520.8 Basis of Payment

The quantity as determined in Section 520.7, Method of Measurement, shall be' paid for at Contract unit price per square meter for Hyrdroseeding which price and payment shall be full compensation for preparing the ground area, for furnishing and placing all the materials required, and for all labor, equipment, tools and incidentals necessary to complete the Item.

Payment will be made under:

Pay Item No.	Description	Unit of Measurement
520	Hydroseeding	Sqaure Meter