TITLE:
Rheological Properties of Cement-Based Grouts Determined by Different Techniques
AUTHORS:
Mohammed Hatem Mohammed, Roland Pusch, Sven Knutsson, Gunnar Hellström
KEYWORDS:
Cement-Grout; Marsh Funnel; Quartz Powder; Rheological Properties; Thixotropic
JOURNAL NAME:
Engineering,
Vol.6 No.5,
March
27,
2014
ABSTRACT: The rheological
properties of cement-based grouts containing talc or palygorskite were investigated for optimizing fluidity and quick strengthening at injection. The
fluidity controls the ability of grout to penetrate fractures and can be
determined by pipe flow tests, Marsh funnel tests, mini-slump cone tests and
rheometer tests. The grouts were 1) Talc for fluidity and strength by reacting
with cement, 2) Palygorskite (attapulgite) for early gelation by being
thixotropic, and 3) Powdered quartz for chemical integrity. The freshly
prepared grouts behaved as Bingham fluids with viscosities from 0.151 to 0.464
Pas and yield stresses 5.2 Pa to 36.7 Pa. Statistical analysis of the flow test
data converted Marsh flow time into viscosity. The pipe flow tests gave 26.5%
higher values than the viscometer for grout with Portland cement and talc, and
about 13.7% lower than the viscometer data for the grout with low-pH cement and
talc. The big Marsh funnel gave values differing by 5.2% - 5.3% from those of
the viscometer for grout with talc and Portland, and Merit 5000 cements. For
grout with palygorskite the viscosity was at least twice that of the other
grouts. Grout fluidity was positively affected by talc and negatively by
palygorskite and early cement hydration.