Two kinds of superplasticizers and four kinds of hardening accelerators were selected to modify the construction waste regeneration brick. Effect of additive amount on the early compressive strength (8 h) of the construction waste regeneration brick was studied, and the characteristics of construction waste regeneration brick at different ages were characterized by XRD. Results showed that the hydration reaction was promoted by an appropriate amount of superplasticizer, and the growth of ettringite crystal nucleus was slowed down. The early compressive strength of regeneration brick reached 10.45 MPa when the addition amount of polycarboxylate superplasticizer was 0.3%. Hardening accelerators such as NaCl, Na2SiO3?9H2O and Na2CO3 can reduce the Ca2+ concentration during hydration reaction process, and inhibit the growth of ettringite crystal nucleus. The early compressive strength of the brick increased by more than 20% when the addition amount of NaCl was 2%. While adding triethanolamine (TEOA), the XRD peak strength of calcium silicate hydrate in early age construction waste regeneration brick was low, and then increased significantly with the brick age increase, indicating that the formation of calcium silicate hydrates was with certain hysteresis.
LU Min
,
XIONG Zu-hong
,
LIN Xia
,
FANG Ke-jing
,
GUO Hua-fang
,
CHEN Yong
. Effects of Additives on the Early Strength Performance of Construction Waste Regeneration Brick[J]. Advances in New and Renewable Energy, 2017
, 5(6)
: 466
-471
.
DOI: 10.3969/j.issn.2095-560X.2017.06.008
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