HCMP and concrete gravity flow pipe benchmarking

Benchmarking study of WProtect 800 train (WP)-coated HCMP and concrete gravity flow pipes

№	Description	HCMP	Reinforced concrete pipe
1	Appearance
2	Diameter range	500 – 3500 (mm), increment 5 сm 300	300-400-500-600-800-1000-1200-1400-1600 (mm)
3	Material	HCMP are made of galvanized rolled steel coated with: zinc + WP polymer (300 um) * Corrosion protection coating is aluminum/zinc alloy. Steel is marketed as pre-dipped coils.	Socket-type round pipes are made of heavy concrete, permeability class W6, W8, W10.
4	Section length (lm)	Up to 13.5	Sections – 2.5 / 3.5 / 5.0
5	Pipe shape	68 x 13 corrugation for up to 800 mm dia., 125 x 26 – over 800 mm dia.	Solid mesh-reinforced concrete
6	Wall thickness (mm)	1.5 / 2.0 / 2.5 / 3.0 / 3.5	50 to 190 mm
7	Load capacity (backfill height)	Up to 12 m	Up to 6 m
8	Product Weight (lm)	d-1,000 mm – 75.5 kg d-1,500 mm – 113,3 kg d-2,000 mm – 147.4 kg	d-1,000 mm – 720 kg d-1,500 mm – 1537 kg d-2,000 mm – 2640 kg
9	Applications	Gravity flow HCMP are used to construct: road/railway culverts; conserved corridors; underground pedestrian crossings; sewage (wastewater) pipelines; drainage pipelines; rainwater collection tanks; bulk storage vessels (silos); formworks; wells;	Reinforced concrete pipes are intended to construct underground gravity flow pipelines for domestic liquid waste, rainwater, underground water, and concrete-friendly process fluids. Road culverts are used any climatic zone.
10	Frost resistance	Immune to hygroscopicity and water saturation. The polymer coating is a protection against water ingress into pipe intermediate layers (steel). As a result, complete pipe cross-section remains unfrozen.	Concrete pipes are prone to water saturation. Freezing and thawing cycles lead to crack formation, reinforcement corrosion and finally to degradation.
11	Corrosion resistance	HCMP fabrication process allows on-line implementation of all extra measures to protect zinc from corrosion and mechanical impact WP coating is applied across the hot zinc surface during production and then becomes soldered with it. This technology is the best practice to protect zinc from corrosion and mechanical impacts known today.	Low. In most cases, corrosion is caused by exposure of concrete pipe inner surface to aggressive media and consequent degradation. Corrosion degrades concrete cover at first, then reinforcement, pipe body, then bore becomes clogged, earth surface caves in, water starts to infiltrate etc.
12	Waterproofing	Not required	Required
13	Electrical corrosion	Laboratory studies prove earth current resistance of HCMP with extra WP* polymer coating.	Prone
14	Microbiological stability	Resistant to microbiological attacks (fungi etc.)	Sensitive
15	Service life	100-120 years	20-30 years
16	Bed type	Sand/gravel or sand/crushed stone	Concrete gutters, local soil, sand, gravel
17	Scope of supply	Pipe section – up to 13.5 lm Coupling bands	Pipe section – up to 5 lm Local block – Watertight screen
18	Installation practice	1. Bed conditioning   2. Section laying 3. Joining with coupling bands   4. Backfilling and soil compaction	1. Bed conditioning 2. Block installation   3. Plastering with waterproofing materials 4. Section laying upon blocks with special machinery 5. Watertight screening and face wall installation
19	Installation costs	No extra utilities and special equipment / machinery No need to arrange a laydown area. Pipe sections can be directly offloaded from a truck to a prepared bed.	A laydown area must be arranged during installation activities to store pipe sections and accessories. Laying operations require special machinery due to heavy weight.
20	Reconditioning practices	Sheathing HCMP specifics allow employing them for reinforcement or reconstruction of existing culverts without dismantling and existing road stripping. Sheathing is a practice to restore a defective pipe capacity. The practice implies insertion of HCMP into the existing facility bore and concrete pouring into the wall-to-wall gap.	Whenever a concrete pipe fails, an existing facility requires complete dismantling including traffic stop and road stripping.
21	Operation and maintenance	Long-term observations over HCMP facilities show virtually zero maintenance costs. The structures are dismantled, as required, and then reused. Maintenance activities are limited to seasonal bore inspection and declogging as required.	Concrete pipe maintenance activities are limited to: reconditioning of internal coating with special materials – either atop or instead of existing coating; corrosion protection with special impregnating primers; reconditioning of failed pipes with exterior reinforcement; reconditioning of shears, cracks, cave-ins, protection of reinforcement (exposed to corrosion);
22	Unit rates as per vendor data	d 1500 mm – approx. 14,300 RUB d 2000 mm – approx. 19,630 RUB	d 1,600 mm – approx. 14,100 RUB d 2,000 mm – approx. 20,200 RUB

* WP extra polymer coating withstands almost all corrosive substances such as acids, alkalis and salts commonly found today in storm water sewers and underground culverts.

The coating is able to withstand sand clay and gravel impact without detriment of adhesion to metal, and provides abrasion resistance equal to over 50 ml bitumen layer.

WP bonds with a galvanized pipe both chemically and physically providing an excellent long-term resistance to mechanical and electrical corrosion and abrasion.

Specimens of corrugated steel sheets coated with WP have been put through microscopic and IR-microspectometrical lab testing after 22 years of service. The specimens have been studied for cracks with an optical microscope. All specimen have shown good physical condition. No evidence of chemical degradation or cracking has been found.

The experts’ findings:
HCMP with extra polymer coating will presumably serve at least 100 years.

Economic performance benchmarking of 1.5 m dia. metal pipes v/s 1.5 m DN RC pipes
(appr. /example).

* Costs are as per 2001 benchmark prices

Advantages of helically corrugated metal pipes.

1. Easy and fast to construct:

HCMP installation does not require heavy construction machinery. Thanks to lightweight, manual assembly can be implemented to reduce construction period.

2. Strength:

Collaboration of HCMP and backfill soil results in structure flexibility and high strength even for thinner steel. Such structures more earthquake-resistant v/s concrete counterparts.

3. Durability:

Many years’ field experience of HCMP with optional polymer coating in road and railway construction proves they are able to serve up to 100 years.

4. Cost effectiveness:

Long-term observations over existing facilities show virtually zero maintenance costs. The structures are dismantled, as required, and then reused.

5. No climatic zone limitations:

Corrugated steel structures perform equally well in arctic cold and tropical heat.

6. Structure costs:

Overall structure weight is considerably lower than reinforcement concrete case; assembly time is 3-5 times less at least, no special machinery and minimum labour – all these allow to save up to 25%.

HCMP – made by MGK

MGK products have been tested and approved for use at road construction sites by “Rosavtodor” Federal Road Agency (Approval No. 01-29 / 13929 dated 24.09.2012, extended through 2016) and by “Avtodor” State Company (Approval No. 1045-PT). Russian regulatory compliance validated by STO 85599441-003-2011 and by Certificate of Conformity No. ROSS RU.AG17.N01 886.
HCMP engineering solutions are based upon Design Standard series 3.501.3-187.10 “Round culverts, bore0.5-2.5 m, helically corrugated – 68h13 and 125h26 mm”

HCMP reference applications in 2012-2014:

1. M-4 highway “Don”
2. M-18 highway “Kola”
3. M-11 highway “Narva”, Ust-Luga port, WHSD (contractor – OOO “Spetstekhnika”)
4. Road construction from beltway to “Pulkovo 1” airport
5. Road no. 121 “SPb-Sortavala (173 km-197 km section)
6. Road maintenance in the Leningrad Oblast
7. Lodeynoye Pole – Tikhvin – Budoga road
8. Podporozhye – Tokari road
9. “Scandinavia” road – Finland border (Torfyanovka)
10. M-7 “Volga” highway (Tatarstan)
11. M-10 “Russia” highway
12. Moscow – St. Petersburg highway
13. M-3 “Ukraine” highway
14. Vyshny Volochek Bypass
15. etc.

HCMP and RC pipe benchmark conclusions:

The average cumulative economic impact from HCMP with extra polymer coating makes up to 15-20%

The greatest economic impact refers to 1.5 m dia. pipes.

In conditions recommended by VSN 176-78, HCMP structures result in up to 30-50% labor savings.

HCMP reduce structure material consumption drastically with their average weight of 1.5 – 3 tons v/s 60-70 m3 and 120-140 tons
(excl. cast-in-situ material) of reinforced concrete.

This also reduces transportation costs related to culvert construction.