precast concrete cable covers

The scope of IS 5820 covers the requirements for both reinforced and unreinforced precast concrete covers used for covering cables, as stated in Clause 1.1. It specifies dimensions, shapes, and minimum average breaking loads for various classes and types of cable covers (Clause 4.1, 8.3, and Table 1). The standard also details testing procedures, including soaking samples before testing and the transverse load test setup with self-aligning steel bearers (Clause B-1.1). Additionally, it governs the use of the Standard Mark under the Bureau of Indian Standards Act, 1986 (Clause 9.2.1). Key dimensional and load data for different classes (EHV, HVP, HV, LV) and types (flat, with peak) are provided in Table 1.

Sources: Clause 1.1, Clause 4.1, Clause 8.3, Clause 9.2.1, Clause B-1.1, Table 1

Key materials specifications from IS 5820 include:

• Concrete Cable Covers Dimensions and Breaking Loads (Table 1, Clause 4.1, 8.3):

• Mixing: Hand mixing, if permitted, must be done on a water-tight platform until uniform color and consistency is achieved (Clause 5.2.1).

• Steel Reinforcement: Steel wire or rod for reinforcement shall conform to IS 432 (Part I & II), IS 1139, IS 1566, or IS 1786 as agreed (Clause 2.4).

• Testing: Covers are soaked in water at 15-20°C for 24 hours before testing; tested wet on self-aligning steel bearers with specified loading rate (Clause 1.1).

These specifications ensure quality and performance of concrete cable covers and reinforcement materials.

Sources: Clause 5.2.1, Table 1 (Clauses 4.1, 8.3), Clause 2.4, Clause 1.1

As per IS 5820 Clause 3.2, precast concrete cable covers are classified mainly into two types based on shape: with peak and flat. The classification by class and typical use is as follows:

Additionally, Table 1 in Clause 5.2.1 provides detailed dimensions and minimum average breaking loads for various classes and types of cable covers, for example:

This classification helps in selecting appropriate cable covers based on voltage rating and mechanical strength requirements. The shapes (with peak or flat) and reinforcement status define the class and application.

Sources: Clause 3.2, Table 1 in Clause 5.2.1

As per Clause 4.1 of IS 5820, the dimensions of reinforced and unreinforced precast concrete cable covers shall conform to Table 1 (not fully provided here). The tolerances specified are:

• Length and width: -3 mm
• Thickness: ±2 mm

Additionally, Clause 3.3 mentions arched type cable covers may have suitable dimensional changes to conform to standard dimensions.

For testing, Clause 1.1 and Fig. 6 describe the transverse test setup where covers are soaked in water (15–20°C for 24 hours), supported on two 50 mm diameter steel bearers spaced 270 mm apart, and loaded centrally at 9000 N/min ±10% through a third 50 mm diameter bearer.

These specifications ensure dimensional accuracy and quality control of cable covers per IS 5820.

Sources: Clause 4.1, Clause 3.3, Clause 1.1, Fig. 6

Key specifications and procedures for manufacture as per IS 5820 include:

• Hand Mixing: When permitted by the engineer-in-charge, hand mixing shall be done on a water-tight platform and continued until the mix is uniform in color and consistency (Clause 5.2.1).

• Concrete Cable Covers Dimensions and Strength: Table 1 specifies dimensions and minimum average breaking loads for various classes and types of precast concrete cable covers. For example, an EHV Class, Type 1 cover with peak shape has dimensions 450 mm (L) × 230 mm (W) × 50 mm (T) with a minimum breaking load of 450 kg.

• Testing Procedure: Covers are soaked in water at 15–20°C for 24 hours before testing. They are supported on two 50 mm diameter steel bearers spaced 270 mm apart, and load is applied centrally at 9000 N/min ±10% through a third 50 mm diameter bearer (Clause 1.1).

• Aggregate Requirements: Aggregates must comply with IS 383-1970; alternative aggregates like blast furnace slag may be used by agreement (Clause 2.2).

These ensure quality and durability in manufacture and testing of concrete cable covers.

Sources: Clause 5.2.1, Table 1, Clause 1.1, Clause 2.2

The general requirements for precast concrete cable covers per IS 5820 include the following key points:

• Hand mixing, if permitted, must be done on a water-tight platform ensuring uniform color and consistency (Clause 5.2.1).
• Dimensions and minimum average breaking loads for various classes and types of cable covers are specified in Table 1 (Clauses 4.1, 8.3). Length and width tolerances are -3 mm, thickness ±2 mm (Clause 4.1).

Table 1: Dimensions and Minimum Average Breaking Load of Precast Concrete Cable Covers

• The use of the Standard Mark is governed by BIS rules (Clause 9.2.1).

These specifications ensure structural integrity and standardization of cable covers for electrical installations.

Sources: Clause 5.2.1, Clause 4.1, Table 1, Clause 9.2.1

Key specifications for sampling as per IS 5820 are:

• Sampling Size: For impact strength testing of reinforced concrete cable covers, take 12 random samples for every consignment of up to 2,000 covers, plus an additional 12 samples for every further 12,000 covers or part thereof (Clause 7.1).

• Batch Testing Procedure: Samples are divided into two equal batches. If any sample in the first batch fails, all samples in the second batch must be tested. If all second batch samples pass, the consignment conforms; if any fail, the consignment does not conform (Clause 8.2.1).

• Pre-Test Conditioning: Covers must be soaked in water at 15–20°C for 24 hours before testing and tested wet (Clause 1.1).

• Test Setup: Covers are supported on two self-aligning steel bearers 50 mm diameter, spaced 270 mm apart. Load is applied centrally at 9,000 N/min ±10% via a third 50 mm diameter steel bearer midway between supports (Clause 1.1).

These ensure consistent and reliable sampling and testing of cable covers.

Sources: Clause 7.1, Clause 8.2.1, Clause 1.1

Key specifications and test criteria for concrete cable covers per IS 5820 are as follows:

• Sample Selection: For transverse strength test of unreinforced concrete covers, 15 samples are randomly selected from each consignment of 3000 covers or part thereof (Clause 7.2).

• Test Procedure: Covers are soaked in water at 15–20°C for 24 hours before testing. Each cover is supported on two self-aligning steel bearers 50 mm diameter, spaced 270 mm apart. Load is applied centrally at a uniform rate of 9000 N/min ±10% through a third 50 mm diameter steel bearer midway between supports (Clause 1.1, Fig. 6).

• Criteria of Conformity:

  • Average breaking load of first 6 covers must meet or exceed Table 1 values.
  • If not, test additional 9 covers.
  • Average of all 15 covers must meet or exceed Table 1 values to conform (Clause 8.3).

• Apparatus: Impact testing apparatus and transverse test apparatus details are given in Figures 5 and 6.

This ensures consistent quality and strength of concrete cable covers as per IS 5820.

Sources: Clause 7.2, Clause 8.3, Clause 1.1, Fig. 5, Fig. 6

As per IS 5820 Clause 9.1, the upper side of each concrete cable cover shall be marked longitudinally by an impression 4 mm deep with the words "ELECTRIC 4" as shown in Figures 1 and 2. Additional identification markings such as the utility name may also be impressed 4 mm deep if desired by the purchaser. Regarding BIS certification, Clause 9.2.1 states that the use of the Standard Mark is governed by the Bureau of Indian Standards Act, 1986, and manufacturers may obtain licensing details from BIS. The marking depth and style ensure clear identification and traceability of cable covers. Figures 1 and 2 illustrate typical marking layouts on flat and peaked cable covers respectively, with letters impressed 4 mm deep. This marking specification ensures durability and legibility of identification on the product surface.

Sources: Clause 9.1, Clause 9.2.1, Fig. 1, Fig. 2

As per IS 5820 Clause 8.2 and Appendix A, the Impact Strength Test for reinforced concrete cable covers involves subjecting samples to two blows from a tup dropped from a height of 460 mm vertically above the center of the cable cover. The test equipment is shown in Fig. 5 (not reproduced here). The key acceptance criterion is that not more than one transverse crack (across the full width) should appear after the two blows. Reinforcement details include mild steel rods of 5 mm and 3 mm diameter as per Fig. 4, with letters impressed 4 mm deep for identification. This test ensures the cable cover's resistance to impact loading. For unreinforced covers, transverse strength tests per Clause 8.3 and Table 1 apply. The test method and acceptance criteria are strictly defined to ensure durability and safety of cable covers under impact conditions.

Sources: Clause 8.2, Clause 8.1, Clause 8.3, Fig. 4, Table 1

As per Clause 8.3 of IS 5820, the transverse strength test for unreinforced concrete cable covers involves testing six samples for their breaking load using the equipment shown in Fig. 6 (Appendix B). The average breaking load of these six covers must meet or exceed the values specified in Table 1 to conform to the standard. If not, an additional nine samples are tested, and the average breaking load of all fifteen samples must meet the Table 1 limits. Failure to meet these limits means the consignment does not conform. This procedure ensures quality control of unreinforced concrete cable covers by verifying their transverse strength. Unfortunately, the exact values from Table 1 and Fig. 6 are not provided in the retrieved context.

Sources: Clause 8.3, Appendix B, Table 1