{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,24]],"date-time":"2026-04-24T04:35:51Z","timestamp":1777005351778,"version":"3.51.4"},"reference-count":38,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2018,11,22]],"date-time":"2018-11-22T00:00:00Z","timestamp":1542844800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000923","name":"Australian Research Council","doi-asserted-by":"publisher","award":["DP170103521"],"award-info":[{"award-number":["DP170103521"]}],"id":[{"id":"10.13039\/501100000923","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000923","name":"Australian Research Council","doi-asserted-by":"publisher","award":["LE170100168"],"award-info":[{"award-number":["LE170100168"]}],"id":[{"id":"10.13039\/501100000923","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000923","name":"Australian Research Council","doi-asserted-by":"publisher","award":["DE180101587"],"award-info":[{"award-number":["DE180101587"]}],"id":[{"id":"10.13039\/501100000923","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>This paper investigates the effect of polypropylene (PP) fibres on the fresh and hardened properties of 3D-printed fibre-reinforced geopolymer mortars. Different percentages of PP fibres ranging between 0.25% and 1.00% by volume were added to an optimised geopolymer mixture. All samples showed reasonable workability and extrudability. In addition, shape-retention ability in the fresh state was investigated as a major requirement for 3D-printing. The compressive strength of the printed specimens was tested in the hardened state in three loading directions, viz. longitudinal, perpendicular, and lateral. The flexural strength of samples was also tested in the longitudinal and lateral directions. In addition, the interlayer bond strength was investigated. Fibre addition seems to influence compressive strengths positively only when the loading is perpendicular to the interface plane. This is due to the preferential fibre alignment parallel to the direction of extrusion. The addition of fibre significantly enhanced the flexural performance of the printed samples. The use of fibre dosages of 0.75 and 1.00 vol % caused deflection-hardening behaviour of the 3D-printed geopolymers and, hence, a significantly higher fracture energy in comparison to specimens without fibre or with lower fibre content. However, an increase in the fibre volume caused some minor reduction in interlayer bond strength. With respect to properties in the fresh state, higher fibre volumes caused better shape-retention ability in the printed samples. The results indicate the possibility of printing fibre-reinforced geopolymers which meet all the necessary properties in both the fresh and hardened states.<\/jats:p>","DOI":"10.3390\/ma11122352","type":"journal-article","created":{"date-parts":[[2018,11,22]],"date-time":"2018-11-22T09:18:25Z","timestamp":1542878305000},"page":"2352","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":274,"title":["Effect of Polypropylene Fibre Addition on Properties of Geopolymers Made by 3D Printing for Digital Construction"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2422-4589","authenticated-orcid":false,"given":"Behzad","family":"Nematollahi","sequence":"first","affiliation":[{"name":"Centre for Sustainable Infrastructure, Faculty of Science, Engineering and Technology, Swinburne University of Technology, 3122 Melbourne, Australia"}]},{"given":"Praful","family":"Vijay","sequence":"additional","affiliation":[{"name":"Institute of Construction Materials, Faculty of Civil Engineering, TU Dresden, 01062 Dresden, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5400-5988","authenticated-orcid":false,"given":"Jay","family":"Sanjayan","sequence":"additional","affiliation":[{"name":"Centre for Sustainable Infrastructure, Faculty of Science, Engineering and Technology, Swinburne University of Technology, 3122 Melbourne, Australia"},{"name":"China University of Mining and Technology, Xuzhou 221116, China"}]},{"given":"Ali","family":"Nazari","sequence":"additional","affiliation":[{"name":"Centre for Sustainable Infrastructure, Faculty of Science, Engineering and Technology, Swinburne University of Technology, 3122 Melbourne, Australia"}]},{"given":"Ming","family":"Xia","sequence":"additional","affiliation":[{"name":"Centre for Sustainable Infrastructure, Faculty of Science, Engineering and Technology, Swinburne University of Technology, 3122 Melbourne, Australia"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8580-5320","authenticated-orcid":false,"given":"Venkatesh","family":"Naidu Nerella","sequence":"additional","affiliation":[{"name":"Institute of Construction Materials, Faculty of Civil Engineering, TU Dresden, 01062 Dresden, Germany"}]},{"given":"Viktor","family":"Mechtcherine","sequence":"additional","affiliation":[{"name":"Institute of Construction Materials, Faculty of Civil Engineering, TU Dresden, 01062 Dresden, Germany"}]}],"member":"1968","published-online":{"date-parts":[[2018,11,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"261","DOI":"10.1080\/17452759.2017.1326724","article-title":"3D printing trends in building and construction industry: A review","volume":"12","author":"Tay","year":"2017","journal-title":"Virtual Phys. 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