ASTM C32 Specifications for Sewer and Manhole Bricks

 ASTM C32 Specifications for Sewer and Manhole Bricks

In order to function properly, manhole and sewer bricks made of shale and clay must meet the requirements of applicable codes such as ASTM C 32. The sewer structure and related structures are designed to transport sewage, industrial waste, and storm water.

Manhole and sewer bricks can be made from clay, shale, or other naturally occurring materials and then fired or heated to create an adequate bond between components and thus achieve adequate strength and durability.

Types of Bricks

Sewer and manhole bricks are graded and classified into several types. Table 1 shows the different types of manhole and sewer bricks.

Table 1: Clay and Shale Sewer and Manhole Brick Classes

Brick classes	Applications
Classes of bricks for sewer structure
Grade SS	Use in structures that require low absorption and resistance to the action of sewage carrying large quantities of abrasive material at velocities greater than 2.4 m/s.
Grade SM	Use in structures that need to withstand the action of sewage carrying abrasive materials at velocities less than 2.4 m/s.
Classes of bricks for manhole
Grade MS	Employ in manholes and catch basins that require low degrees of abrasive resistance, high and uniform degree of resistance to frost action and disintegration.
Grade MM	Use in manholes require high degrees of abrasive resistance, moderate and nonuniform degree of resistance to frost action and disintegration.

Properties

1. Bricks should have a rectangular cross section and straight edges and corners to a large extent.
2. On the backside of sewer and manhole bricks, a maximum of 5mm depression or kiln marks are permitted.
3. Sewer brick surfaces and sides must be smooth and uniform.
4. The surface of manhole bricks should be smooth and evenly textured.
5. Table 2 displays the physical properties of clay and shale bricks.

Table 2: Physical Properties of Clay and Shale Manhole and Sewer Bricks

Brick type	Minimum Compressive Strength, Average Gross Area, (MPa)	Minimum Compressive Strength, Average Gross Area, (MPa)	Maximum Water Absorption by 5-h Boiling, %	Maximum Water Absorption by 5-h Boiling, %
	Average of 5 Brick	Individual	Average of 5 Brick	Individual
Grade SS Sewer brick	55	41	6	9
Grade SM Sewer brick	34	26	12	15
Grade MS Manhole brick	21	17	17	20
Grade MM Manhole brick	17	15	22	25

Applications

1. Drainage structures for sewage, industrial waste, and storm water transport.
2. Catch basins and manholes