Term
| All-lightweight concrete is made of... |
|
Definition
| all lightweight aggregates |
|
|
Term
| Sand lightweight concrete is made of... |
|
Definition
| coarse lightweight aggregate and natural sand. |
|
|
Term
| Structural lightweight concrete has an air-dry density in the range of... |
|
Definition
| 1350 to 1850 kg/m3 (85 to 115 pcf) |
|
|
Term
| Structural lightweight concrete has a 28-day compressive strength in excess of... |
|
Definition
|
|
Term
| Test for density of structural lightweight concrete is provided in ASTM ____. |
|
Definition
|
|
Term
| The primary use of structural lightweight concrete is... |
|
Definition
| to reduce the dead-load weight in concrete members, such as floors in high-rise buildings. |
|
|
Term
| Processed structural lightweight aggregates should meet the requirements of ASTM ____ |
|
Definition
|
|
Term
| Types lightweight aggregates... |
|
Definition
| rotary kiln expanded clays, shales adn slates; sintering grate expanded shales and slates; pelletized or extruded fly ash; expanded slags; naturally occurring pumice and scoria |
|
|
Term
| Structural lightweight aggregates have densities ranging from... |
|
Definition
| 560 to 1120 kg/m3 (35 to 70 pcf) |
|
|
Term
| Lightweight aggregates may absorb ____% to ____% water by weight of dry material. |
|
Definition
|
|
Term
| What do you do to control the uniformity of structural lightweight concrete mixtures? |
|
Definition
| Prior to batching the aggregates are pre-wetted but not saturated. |
|
|
Term
| The compressive strength of structural lightweight concrete is usually related to the ____________________ rather than to ____________. |
|
Definition
| cement content at a given slump and air content; a water-to-cement ratio |
|
|
Term
| Typical compressive strengths range from _____ to _______. |
|
Definition
| 20 to 35 MPa (3000 to 5000 psi) |
|
|
Term
| Lightweight concrete mix design will vary ____ from one aggregate source or type to another. |
|
Definition
|
|
Term
| Air content of lightweight concrete are generally between _____% and ____%, depending on maximum size of coarse aggregate used and exposure condition. |
|
Definition
|
|
Term
| Testing for air content in lightweight concrete should be performed by ________ |
|
Definition
Volumetric method
ASTM C-173
AASHTO T-196 |
|
|
Term
| With lightweight concrete measured slump at the batch plant will generally be appreciably ______ than the slump at the site. |
|
Definition
|
|
Term
| Pumping lightweight concrete can especially aggravate slump _____ |
|
Definition
|
|
Term
| Due to lower aggregate density, structural lightweight concrete does not slump as much as normal-weight concrete with the same workability. True or False |
|
Definition
|
|
Term
| Lightweight concrete with higher slumps, the large particles tend... |
|
Definition
| to float to the surface, making finishing difficult. |
|
|
Term
| Vibration can not be used effectively to consolidate lightweight concrete. True of False |
|
Definition
| False - Vibration can be used |
|
|
