M15 in the building that the strength of mortar? What is the unit?
Masonry mortar according to the compressive strength is divided into M M M M7 M M25 and other six strength levels The strength of mortar in addition to the composition of the mortar itself and the ratio of the impact, but also with the grass-roots water absorption performance Compressive strength Design value Unit: MPa (MPa, referred to as MPa) 1MPA = 10 Atmospheric pressure = 103323kg / cm2
Feldspar feldspar is a broad name of basic aluminosilicate, for example: feldspars containing alkali metal potassium (potassium oxide-alumina-silica) are called "potash feldspar" and contain Sodium (sodium oxide - alumina - silica) feldspar is called "albite", but most feldspars are made from these two types.
The mortar strength grade is determined by the compressive strength values maintained at 28 d under the standard conditions [at (20 ± 2) ° C and relative humidity of 90% or more) using cubic cubes with a side length of 7
