Superblock Ltd.

ENGINEERING PROPERTIES OF SUPERBLOCK

1. Density The density of SUPERBLOCK is about 550-600 kg/m3, which is approximately two times lighter than water, four times lighter than concrete, and three times lighter than fire clay brick.

2. Modulus of Elasticity. E The Modulus of Elasticity (E) of SUPERBLOCK lies within the range of 18,000 to 28,000 kg/cm².

3. Compressive strength The compressive strength of SUPERBLOCK is about 40-50 kg/cm². This means that each unit of SUPERBLOCK (size: 20 x 60 x 7.5 cm) can take at least 18 tons of compressive force.

4. Modulus of Rupture (Flexural Strength) The Modulus of Rupture of SUPERBLOCK is about 23 kg/cm².

5. Fire Rating Non-loadbearing wall built from 7.5 and 9 cm. thick SUPERBLOCK has the fire rating according to the British Standard: BS 476 Part 22: 1987 Fire Tests on building materials and structures: Methods for determination of the fire resistance of non-loadbearing elements of construction and to the Australian Standard : As 3700:1988 equal 3.85 and 4 hours.

6. Sound Insulation STC (Sound Transmission Class) is an index, which is used to indicate the sound insulation capability of construction material. STCs (Sound Transmission Class) for different types of SUPERBLOCK walls are given in Table 1.

Table 1 : STCs for different types of SUPERBLOCK walls
Thickness of SUPERBLOCK wall (cm)	Coating (if applicable)	STC
9 cm	None	42
9 cm	10 mm sand/cement render both sides	43
9cm/5cm cavity/9cm	None	44
9cm/5cm cavity/9cm	10 mm sand/cement render both sides	47
15 cm	None	43
15 cm	10 mm sand/cement render both sides	45
20 cm	None	46
20 cm	10 mm sand/cement render both sides	47

7. Sound Absorption Sound Absorption Coefficient is an index used to indicate the sound absorption capability of construction material. This value is the ratio of sound energy that is absorbed at different sound frequencies. The Sound Absorption Coefficients of SUPERBLOCK at different mean frequency are given in Table 2.

Table 2 : Sound Absorption Coefficients of SUPERBLOCK
Mean frequency (Hz)	125	250	500	1000	2000	4000
Sound Absorption Coefficient	0.05	0.10	0.15	0.25	0.20	0.25

8. Thermal Resistance The thermal resistance "R" of 7.5 cm-thick SUPERBLOCK wall is equal to 0.843 m² ºC/W. This R value can then be used to calculate the rate of thermal transmission by using the following formula.

	Rate of Thermal Transmission =	T	(W/m²)
		R

	R = Thermal Resistance (m² ºC/W)
	T = The difference between the inside and outside temperatures (ºC)
	For Thailand, the average outside temperature is 36 ºC and the comfortable inside temperature is 24 ºC. Therefore, the proper value for T is 36 - 24 = 12 ºC. From the above formula, the Rate of Thermal Transmission of SUPERBLOCK is 12/0.843=14 W/m².

9. Thermal Expansion Coefficient The Thermal Expansion Coefficient of SUPERBLOCK is about 8 x 10-6 - 10 x 10-6 / ºC, which is close to the Thermal Expansion Coefficient of concrete as shown in Table 3.

Table 3 : Thermal Expansion Coefficients for different types of material
	SUPERBLOCK	Fire Clay Brick	Concrete
Thermal Expansion Coefficient / ºC	8.0x10-6-10.0x10-6	4.6x10-6	9.4x10-6

10. Drying Shrinkage In general, construction material that adsorbs water will shrink when water loss occurs. The rate of this drying shrinkage depends of several factors, including type of mineral binding agent and the amount of ultra-fine pores in the material. The drying shrinkage of SUPERBLOCK when the moisture content (by weight) is reduced from 30% at the completion of the production process to an equilibrium moisture content of 5-7 % at usage is about 0.2 mm/m. As shown in Table 4, this value is much less than the drying shrinkage of concrete and fire clay brick. This is due to the fact that the autoclaving process during the production of SUPERBLOCK considerably reduces the amount of very fine(<10 mm) pores.

Table 4 : Drying Shrinkage for different types of material
	SUPERBLOCK	Fire Clay Brick	Concrete
Drying shrinkage (mm/m)	0.2	1.8	0.7