The HLSA prepared in lab were synthesized by industrial-grade aluminum sulfate ([Al.sub.2][(S[O.sub.4]).sub.3]-18[H.sub.2]O), chemically pure sodium fluoride (NaF), chemically pure triethanolamine ([(HOC[H.sub.2]C[H.sub.2]).sub.3]N), chemically pure polyacrylamide (-[[C[H.sub.2]CH].sub.n]CON[H.sub.2]-), and chemically pure phosphoric acid ([H.sub.3]P[O.sub.4]).
HLSA was light green homogeneous liquid in appearance with density of 1.61 g/[cm.sup.3] and solid content of 40.5%.
The setting time of cement with HLSA was measured according to Chinese Building Materials Standards JC 477-2005 with water to cement ratio (W/C) 0.40; the dosage of setting accelerator was 6%, 7%, and 8% (by mass of cement) respectively.
The specimens were prepared and cured in molds for 24 h under the condition of temperature 20 [+ or -] 2[degrees]C and RH over 90%; then they were demoulded and tested for 1d compressive strength immediately; the percentage of mortar in addition to HLSA compressive strength growth at 1 d was characterized by the following:
where [C.sub.1](%) was growth rate of compressive strength at 1 d, [C.sub.(a1)] were compressive strength of specimens containing HLSA at 1 d, and [C.sub.(b1)] were compressive strength of blank specimens at 1 d.
where [C.sub.28](%) was retention percentage of compressive strength at 28 d, [C.sub.(H28)] were compressive strength of specimens containing HLSA at 28 d, and [C.sub.(B28)] were compressive strength of blank specimens at 28 d.