Abstract: In plain mortar, the water film thickness (WFT) has been found to play a key role in the fresh properties. However, in fiber-reinforced mortar, the role of WFT has not been investigated yet. In this research, basalt fibers of different lengths were added to the mortar, and the dynamic and static flowability, cohesiveness, adhesiveness, and packing density were tested to study the effects of fiber length on the packing density and WFT, and the combined effects of fiber length and WFT on the fresh properties. The results showed that in fiber-reinforced mortar, the WFT also plays a key role, whereas the fiber length exerts its influences through the indirect effects on the packing density and WFT and the direct effect on fiber-mortar interaction. Basically, an increase in fiber length decreases the packing density and WFT, decreases the dynamic and static flowability needed for placing, increases the cohesiveness needed for avoiding segregation, and, quite unexpectedly, decreases the adhesiveness needed for rendering and spraying applications. Regression analysis yielded good correlation of the fresh properties to fiber length and WFT, and best-fit formulas for the mix design for basalt fiber-reinforced mortar were obtained.

纤维长度与水膜厚度对玄武岩纤维增强砂浆新拌性能的影响研究

[1]Abbass W, Khan MI, Mourad S, 2018. Evaluation of mechanical properties of steel fiber reinforced concrete with different strengths of concrete. Construction and Building Materials, 168:556-569.

[2]Ahari RS, 2018. Role of water film thickness on rheological characteristics of self-consolidating concrete containing silica fume. Journal of New Approaches in Civil Engineering, 2(2):1-10.

[3]Ali M, Liu A, Sou H, et al., 2012. Mechanical and dynamic properties of coconut fibre reinforced concrete. Construction and Building Materials, 30:814-825.

[4]AQSIQ (General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China), 2007. Common Portland Cement, GB 175–2007. Standardization Administration of China, Beijing, China (in Chinese).

[5]Banfill PFG, 1994. Rheological methods for assessing the flow properties of mortar and related materials. Construction and Building Materials, 8(1):43-50.

[6]Banfill PFG, Starrs G, Derruau G, et al., 2006. Rheology of low carbon fibre content reinforced cement mortar. Cement and Concrete Composites, 28(9):773-780.

[7]CEN (European Committee for Standardization), 2010a. Testing Fresh Concrete–Part 9: Self-compacting Concrete– V-funnel Test, EN 12350-9:2010. CEN, Brussels, Belgium.

[8]CEN (European Committee for Standardization), 2010b. Testing Fresh Concrete–Part 11: Self-compacting Concrete– Sieve-segregation Test, EN 12350-11:2010. CEN, Brussels, Belgium.

[9]CEN (European Committee for Standardization), 2019. Testing Fresh Concrete–Part 8: Self-compacting Concrete– Slump-flow Test, EN 12350-8:2019. CEN, Brussels, Belgium.

[10]Chen JJ, Ng PL, Kwan AKH, et al., 2019. Lowering cement content in mortar by adding superfine zeolite as cement replacement and optimizing mixture proportions. Journal of Cleaner Production, 210:66-76.

[11]Chen JJ, Ng PL, Chu SH, et al., 2020. Ternary blending with metakaolin and silica fume to improve packing density and performance of binder paste. Construction and Building Materials, 252:119031.

[12]Chu SH, Li LG, Kwan AKH, 2018. Fibre factors governing the fresh and hardened properties of steel FRC. Construction and Building Materials, 186:1228-1238.

[13]Claisse PA, Lorimer P, Al Omari M, 2001. Workability of cement pastes. ACI Materials Journal, 98(6):476-482.

[14]Cordeiro GC, Toledo Filho RD, Tavares LM, et al., 2011. Influence of particle size and specific surface area on the pozzolanic activity of residual rice husk ash. Cement and Concrete Composites, 33(5):529-534.

[15]de Schutter G, Bartos PJM, Domone P, et al., 2008. Self-compacting Concrete. CRC Press, Boca Raton, USA, p.296.

[16]Eidan J, Rasoolan I, Rezaeian A, et al., 2019. Residual mechanical properties of polypropylene fiber-reinforced concrete after heating. Construction and Building Materials, 198:195-206.

[17]Felekoğlu B, Türkel S, Baradan B, 2007. Effect of water/ cement ratio on the fresh and hardened properties of self-compacting concrete. Building and Environment, 42(4):1795-1802.

[18]Ghernouti Y, Rabehi B, Bouziani T, et al., 2015. Fresh and hardened properties of self-compacting concrete containing plastic bag waste fibers (WFSCC). Construction and Building Materials, 82:89-100.

[19]Gribniak V, Arnautov AK, Kaklauskas G, et al., 2015. Investigation on application of basalt materials as reinforcement for flexural elements of concrete bridges. The Baltic Journal of Road and Bridge Engineering, 10(3):201-206.

[20]Hunger M, Brouwers HJH, 2009. Flow analysis of water– powder mixtures: application to specific surface area and shape factor. Cement and Concrete Composites, 31(1):39-59.

[21]Islam MS, Ahmed SJU, 2018. Influence of jute fiber on concrete properties. Construction and Building Materials, 189:768-776.

[22]Kismi M, Saint-Arroman JC, Mounanga P, 2012. Minimizing water dosage of superplasticized mortars and concretes for a given consistency. Construction and Building Materials, 28(1):747-758.

[23]Kwan AKH, Li LG, 2012. Combined effects of water film thickness and paste film thickness on rheology of mortar. Materials and Structures, 45(9):1359-1374.

[24]Kwan AKH, Li LG, 2014. Combined effects of water film, paste film and mortar film thicknesses on fresh properties of concrete. Construction and Building Materials, 50: 598-608.

[25]Kwan AKH, Fung WWS, Wong HHC, 2010. Water film thickness, flowability and rheology of cement-sand mortar. Advances in Cement Research, 22(1):3-14.

[26]Kwan AKH, Li LG, Fung WWS, 2012. Wet packing of blended fine and coarse aggregate. Materials and Structures, 45(6):817-828.

[27]Kwan AKH, Chan KW, Wong V, 2013. A 3-parameter particle packing model incorporating the wedging effect. Powder Technology, 237:172-179.

[28]Kwan AKH, Wong V, Fung WWS, 2015. A 3-parameter packing density model for angular rock aggregate particles. Powder Technology, 274:154-162.

[29]Li LG, Kwan AKH, 2011. Mortar design based on water film thickness. Construction and Building Materials, 25(5):2381-2390.

[30]Li LG, Kwan AKH, 2013. Concrete mix design based on water film thickness and paste film thickness. Cement and Concrete Composites, 39:33-42.

[31]Li LG, Kwan AKH, 2014. Packing density of concrete mix under dry and wet conditions. Powder Technology, 253: 514-521.

[32]Li LG, Kwan AKH, 2017. Roles of superplasticiser dosage, water film thickness and slurry film thickness in flowability of cementitious paste. Advances in Cement Research, 29(7):287-301.

[33]Li LG, Lin CJ, Chen GM, et al., 2017a. Effects of packing on compressive behaviour of recycled aggregate concrete. Construction and Building Materials, 157:757-777.

[34]Li LG, Zhu J, Zhao ZW, et al., 2017b. Roles of water film thickness and polypropylene fibre content in fresh properties of mortar. Advances in Cement Research, 29(2):71-80.

[35]Li LG, Zhao ZW, Zhu J, et al., 2018a. Combined effects of water film thickness and polypropylene fibre length on fresh properties of mortar. Construction and Building Materials, 174:586-593.

[36]Li LG, Chu SH, Zeng KL, et al., 2018b. Roles of water film thickness and fibre factor in workability of polypropylene fibre reinforced mortar. Cement and Concrete Composites, 93:196-204.

[37]Li LG, Zeng KL, Ouyang Y, et al., 2019a. Basalt fibre-reinforced mortar: rheology modelling based on water film thickness and fibre content. Construction and Building Materials, 229:116857.

[38]Li LG, Zhuo HX, Zhu J, et al., 2019b. Packing density of mortar containing polypropylene, carbon or basalt fibres under dry and wet conditions. Powder Technology, 342: 433-440.

[39]Li LG, Huang ZH, Tan YP, et al., 2019c. Recycling of marble dust as paste replacement for improving strength, microstructure and eco-friendliness of mortar. Journal of Cleaner Production, 210:55-65.

[40]Li LG, Ouyang Y, Zhuo ZY, et al., 2021a. Adding ceramic polishing waste as filler to reduce paste volume and improve carbonation and water resistances of mortar. Advances in Bridge Engineering, 2:3.

[41]Li LG, Xiao BF, Fang ZQ, et al., 2021b. Feasibility of glass/basalt fiber reinforced seawater coral sand mortar for 3D printing. Additive Manufacturing, 37:101684.

[42]Li LG, Feng JJ, Zhu J, et al., 2021c. Pervious concrete: effects of porosity on permeability and strength. Magazine of Concrete Research, 73(2):69-79.

[43]Li LG, Zheng JY, Ng PL, et al., 2021d. Synergistic cementing efficiencies of nano-silica and micro-silica in carbonation resistance and sorptivity of concrete. Journal of Building Engineering, 33:101862.

[44]Mehdipour I, Khayat KH, 2017. Effect of particle-size distribution and specific surface area of different binder systems on packing density and flow characteristics of cement paste. Cement and Concrete Composites, 78:120-131.

[45]Midorikawa T, Pelova GI, Walraven JC, 2009. Application of “the water layer model” to self-compacting mortar with different size distributions of fine aggregate. Heron, 54(2-3):73-99.

[46]Ng PL, Kwan AKH, Li LG, 2016. Packing and film thickness theories for the mix design of high-performance concrete. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 17(10):759-781.

[47]Okamura H, Ouchi M, 2003. Self-compacting concrete. Journal of Advanced Concrete Technology, 1(1):5-15.

[48]Powers TC, 1968. The Properties of Fresh Concrete. John Wiley & Sons, New York, USA, p.664.

[49]Poznyak OR, Kirakevych II, Stechyshyn MS, 2014. Properties of self-compacting concrete with basalt fiber. Academic Journals & Conferences of Lviv Polytechnic National University, (781):149-154.

[50]Shi CJ, Jiao DW, Zhang J, et al., 2018. Design of high performance concrete with multiple performance requirements for #2 Dongting Lake Bridge. Construction and Building Materials, 165:825-832.

[51]Sun Y, Wang ZL, Gao QF, et al., 2018. A new mixture design methodology based on the packing density theory for high performance concrete in bridge engineering. Construction and Building Materials, 182:80-93.

[52]Wong HHC, Kwan AKH, 2008. Rheology of cement paste: role of excess water to solid surface area ratio. Journal of Materials in Civil Engineering, 20(2):189-197.

[53]Wong V, Kwan AKH, 2014. A 3-parameter model for packing density prediction of ternary mixes of spherical particles. Powder Technology, 268:357-367.

[54]Wu Q, An XH, 2014. Development of a mix design method for SCC based on the rheological characteristics of paste. Construction and Building Materials, 53:642-651.

[55]Wu Q, An XH, Liu CN, 2014. Effect of polycarboxylate-type superplasticizer on the paste fluidity based on the water film thickness of flocs. Science China Technological Sciences, 57(8):1522-1531.

[56]Yu AB, Bridgwater J, Burbidge A, 1997. On the modelling of the packing of fine particles. Powder Technology, 92(3):185-194.

[57]Zhang RX, Panesar DK, 2017. New approach to calculate water film thickness and the correlation to the rheology of mortar and concrete containing reactive MgO. Construction and Building Materials, 150:892-902.