TY - JOUR
T1 - Development of high performance lightweight concrete using ultra high performance cementitious composite and different lightweight aggregates
AU - Lu, Jian Xin
AU - Shen, Peiliang
AU - Ali, Hafiz Asad
AU - Poon, Chi Sun
N1 - Funding Information:
The authors wish to thank the financial support from the Hong Kong Polytechnic University . The first author would like to appreciate the Teaching Postgraduate Studentship Scheme. The technical assistance of Ms. Dorothy Chan in conducting the MIP and BET tests are gratefully acknowledged. Thanks are also due to Dr. Ting Fai Kong (Department of Industrial and Systems Engineering) for his help in performing the micro-CT experiment.
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/11
Y1 - 2021/11
N2 - To reduce the dead load of concrete structures, this study developed a high performance lightweight aggregate concrete (HPLAC) by combining the use of ultra high performance cementitious composite (UHPC) and different types of aluminosilicate lightweight aggregates (LWAs). The physicochemical properties of two types of LWAs (i.e. expanded clay and expanded shale) influencing the HPLAC were elaborated and compared. The composition distribution and micromechanical properties in the interfacial regions of paste and LWAs were revealed by elemental mapping and nanoindentation. The results showed that the incorporation of the clay LWAs or shale LWAs in the HPLAC led to similar density and thermal conductivity values, while the use of the shale LWAs induced a lower water absorption and higher strength of HPLAC as compared to the clay LWAs due to the fine pore structure and higher pozzolanic activity of the former. The internal curing effect provided by the pre-wetted shale LWAs was more efficient in enhancing the hydration of binder, and the Al dissolution from the shale LWAs further densified the interfacial bonding to form a dense rim surrounding LWAs, resulting in improved micromechanical properties at the interface. The X-ray CT results indicated that the adoption of UHPC was beneficial to preventing segregation of the LWAs and steel fibers in the HPLAC. By virtue of the physical-chemical interactions of LWAs, the synergetic use of UHPC and pre-wetted shale LWAs was able to produce an HPLAC with high structural efficiency, good thermal insulation, low autogenous shrinkage and permeability.
AB - To reduce the dead load of concrete structures, this study developed a high performance lightweight aggregate concrete (HPLAC) by combining the use of ultra high performance cementitious composite (UHPC) and different types of aluminosilicate lightweight aggregates (LWAs). The physicochemical properties of two types of LWAs (i.e. expanded clay and expanded shale) influencing the HPLAC were elaborated and compared. The composition distribution and micromechanical properties in the interfacial regions of paste and LWAs were revealed by elemental mapping and nanoindentation. The results showed that the incorporation of the clay LWAs or shale LWAs in the HPLAC led to similar density and thermal conductivity values, while the use of the shale LWAs induced a lower water absorption and higher strength of HPLAC as compared to the clay LWAs due to the fine pore structure and higher pozzolanic activity of the former. The internal curing effect provided by the pre-wetted shale LWAs was more efficient in enhancing the hydration of binder, and the Al dissolution from the shale LWAs further densified the interfacial bonding to form a dense rim surrounding LWAs, resulting in improved micromechanical properties at the interface. The X-ray CT results indicated that the adoption of UHPC was beneficial to preventing segregation of the LWAs and steel fibers in the HPLAC. By virtue of the physical-chemical interactions of LWAs, the synergetic use of UHPC and pre-wetted shale LWAs was able to produce an HPLAC with high structural efficiency, good thermal insulation, low autogenous shrinkage and permeability.
KW - Durability
KW - High performance lightweight concrete
KW - Micromechanical properties
KW - Pozzolanic reactivity
KW - Ultra high performance cementitious composite
UR - http://www.scopus.com/inward/record.url?scp=85115808002&partnerID=8YFLogxK
U2 - 10.1016/j.cemconcomp.2021.104277
DO - 10.1016/j.cemconcomp.2021.104277
M3 - Journal article
AN - SCOPUS:85115808002
SN - 0958-9465
VL - 124
JO - Cement and Concrete Composites
JF - Cement and Concrete Composites
M1 - 104277
ER -