Assertion: mortar's cement | /r/HasProperty | produced
Facets:
value: by burning argillaceous limestones
type: MANNER
value: occasionally
type: DEGREE
Source sentences:
text: Addition of silica fume can yield exceptionally high strengths, and cements containing 5–20% silica fume are occasionally produced, with 10% being the maximum allowed addition under EN 197-1.
text: "Natural" cements corresponding to certain cements of the pre-Portland era, are produced by burning argillaceous limestones at moderate temperatures.