Washout and Strength Behaviors of Underwater Concrete Containing Welan Gum and Slump Retainers

Authors

  • Joseph Jean Assaad

    Department of Civil & Environmental Engineering, Faculty of Engineering, University of Balamand, Koura Campus, Tripoli P.O. Box 100, Lebanon

DOI:

https://doi.org/10.30564/jbms.v8i3.13659
Received: 18 June 2026 | Revised: 6 July 2026 | Accepted: 16 July 2026 | Published Online: 13 August 2026

Abstract

This study explores the synergistic effects of welan gum-based anti-washout admixtures (AWAs) and slump-retaining polycarboxylate ether superplasticizers (SK-PCEs) in underwater concrete (UWC). It addresses the inherent challenge of simultaneously achieving sufficient viscosity to resist washout while maintaining adequate workability for extended placement. Three mortar series incorporating different water-to-binder (w/b) ratios and AWA/SK-PCE combinations were investigated through tests of time-dependent flow behavior, washout resistance, V-funnel flow time, bleeding, setting time, and compressive strength. Test results showed that the incorporation of SK-PCE is efficient to reduce the rate of flow loss over time, yet without altering the V-funnel flow time (i.e., viscosity) measurements. At a high w/b of 0.5, the AWA's ability to trap mixing water (bleeding) and reduce washout loss was slightly disrupted by the SK-PCE. However, at lower w/b of 0.42 and 0.36, the negative SK-PCE impact becomes negligible, suggesting that the inherent particle packing and naturally cohesive mixtures compensate for the dispersive energy provided by the PCE polymers. While the incorporation of AWA prolonged setting and reduced late-age compressive strength, the addition of SK-PCE alongside AWA had a neutral effect. From a practical standpoint, this reflects the possibility of adjusting the AWA and SK-PCE couple in order to optimize washout resistance and workability drop without dramatically compromising the setting and durability of UWC mixtures.

Keywords:

Welan Gum; Polycarboxylate Ethers; Underwater Concrete; Washout Loss; Compressive Strength

References

[1] ACI Committee 546, 2010. 546.2R-10: Guide to Underwater Repair of Concrete. American Concrete Institute: Farmington Hills, MI, USA. DOI: https://doi.org/10.14359/51663806

[2] Wang, Y., Chen, S., Qiu, L., et al., 2023. Experimental study on the slump-flow underwater for anti-washout concrete. Construction and Building Materials. 365, 130026. DOI: https://doi.org/10.1016/j.conbuildmat.2022.130026

[3] Horszczaruk, E., Brzozowski, P., 2014. Bond strength of underwater repair concretes under hydrostatic pressure. Construction and Building Materials. 72, 167–173. DOI: https://doi.org/10.1016/j.conbuildmat.2014.08.020

[4] Assaad, J.J., Daou, Y., Harb, J., 2011. Use of CEM Approach to Develop and Optimize High-Performance Underwater Concrete. Journal of Materials in Civil Engineering. 23(7), 1094–1102. DOI: https://doi.org/10.1061/(ASCE)MT.1943-5533.0000254

[5] Assaad, J.J., Issa, C.A., 2013. Mechanisms of strength loss in underwater concrete. Materials and Structures. 46(10), 1613–1629. DOI: https://doi.org/10.1617/s11527-012-0004-2

[6] Issa, C.A., Assaad, J.J., 2015. Bond of tension bars in underwater concrete: effect of bar diameter and cover. Materials and Structures. 48(11), 3457–3471. DOI: https://doi.org/10.1617/s11527-014-0414-4

[7] Yan, W., Cui, W., Qi, L., 2022. Simulation of underwater concrete movement in flowing water using DEM-CFD coupling method. Construction and Building Materials. 319, 126134. DOI: https://doi.org/10.1016/j.conbuildmat.2021.126134

[8] Zhang, Y., Zhao, Q., Liu, C., et al., 2016. Properties comparison of mortars with welan gum or cellulose ether. Construction and Building Materials. 102, 648–653. DOI: https://doi.org/10.1016/j.conbuildmat.2015.10.116

[9] Sun, Z., Xu, B., Yang, Z., et al., 2025. Resolving rheological dilemma in non-dispersible underwater concrete: Conflict between fluidity and anti-washout. Construction and Building Materials. 493, 143258. DOI: https://doi.org/10.1016/j.conbuildmat.2025.143258

[10] Pan, Y., Lu, Z., Li, X., et al., 2026. Enhanced flowability of metakaolin-blended cement through the synergistic effect of polycarboxylate superplasticizer and retarder: Competitive adsorption and retarded hydration. Cement and Concrete Research. 202, 108142. DOI: https://doi.org/10.1016/j.cemconres.2026.108142

[11] Luo, G., Liu, M., Li, H., et al., 2024. Importance of adsorption compared with complexation for retarding C3S hydration via adding sodium gluconate. Cement and Concrete Research. 186, 107686. DOI: https://doi.org/10.1016/j.cemconres.2024.107686

[12] Li, S., Pang, H., Zhang, J., et al., 2019. Synthesis and performance of a novel amphoteric polycarboxylate superplasticizer with hydrolysable ester group. Colloids and Surfaces A: Physicochemical and Engineering Aspects. 564, 78–88. DOI: https://doi.org/10.1016/j.colsurfa.2018.11.043

[13] Liu, X., Guan, J., Lai, G., et al., 2017. Performances and working mechanism of a novel polycarboxylate superplasticizer synthesized through changing molecular topological structure. Journal of Colloid and Interface Science. 504, 12–24. DOI: https://doi.org/10.1016/j.jcis.2017.05.025

[14] Ma, R., Wang, Y., Li, H., et al., 2023. Progress in the polycarboxylate superplasticizer and their structure-activity relationship – A review. Materials Today Communications. 35, 105838. DOI: https://doi.org/10.1016/j.mtcomm.2023.105838

[15] Lai, G., Liu, X., Song, X., et al., 2024. A mechanistic study on the effectiveness of star-like and comb-like polycarboxylate superplasticizers in cement pastes. Cement and Concrete Research. 175, 107389. DOI: https://doi.org/10.1016/j.cemconres.2023.107389

[16] Li, W., Tan, S., 2026. Effect of functional groups on the dispersion behavior and stability of polycarboxylate superplasticizers in calcium sulfate hemihydrate systems. Materials Letters. 413, 140439. DOI: https://doi.org/10.1016/j.matlet.2026.140439

[17] Pei, J., Li, J., Lv, X., et al., 2026. Synthesis of an early-age strength polycarboxylate lanthanum complex superplasticizer and its impact on cement hydration. Construction and Building Materials. 518, 145820. DOI: https://doi.org/10.1016/j.conbuildmat.2026.145820

[18] Burhan, L., Ghafor, K., Mohammed, A., 2020. Testing and Evaluation of Flowability, Viscosity and Long-Term Compressive Strength of Cement Modified with Polymeric Admixture WR Superplasticizer. IOP Conference Series: Materials Science and Engineering. 737(1), 012066. DOI: https://doi.org/10.1088/1757-899X/737/1/012066

[19] Chen, X., Tang, X., Zhang, C., et al., 2022. Synthesis and property of EPEG ‐based polycarboxylate ether superplasticizers via RAFT polymerization. Polymer Engineering & Science. 62(9), 2769–2778. DOI: https://doi.org/10.1002/pen.26060

[20] Chen, Z., Chen, B., Tang, Y., et al., 2024. Innovative strategies for time-release PCE design and cement paste flowability control. Cement and Concrete Composites. 154, 105785. DOI: https://doi.org/10.1016/j.cemconcomp.2024.105785

[21] Salih, M.A., Ahmed, S.K., Mohammed, A.S., 2025. Performance of Sustainable Underwater Concrete Containing GGBS and Micro Silica with Anti-Washout. Civil Engineering Journal. 11(12), 5238–5255. DOI: https://doi.org/10.28991/CEJ-2025-011-12-018

[22] Burhan, L., Ghafor, K., Mohammed, A., 2020. Enhancing the Fresh and Hardened Properties of the Early Age Concrete Modified with Powder Polymers and Characterized Using Different Models. Advances in Civil Engineering Materials. 9(1), 227–249. DOI: https://doi.org/10.1520/ACEM20190087

[23] Nili, M., Sabziparvar, N., Sabziparvar, A., 2023. Creep and drying shrinkage of recycled aggregate concrete containing cement and alkali activated slag produced by water reduction method (WRM) and equivalent mortar volume (EMV). Construction and Building Materials. 395, 132153. DOI: https://doi.org/10.1016/j.conbuildmat.2023.132153

[24] ASTM International, 2023. ASTM C230/C230M-23: Standard Specification for Flow Table for Use in Tests of Hydraulic Cement. ASTM International: West Conshohocken, PA, USA. DOI: https://doi.org/10.1520/C0230_C0230M-23

[25] ASTM International, 2026. ASTM C232/C232M-26: Standard Test Method for Bleeding of Concrete. ASTM International: West Conshohocken, PA, USA. DOI: https://doi.org/10.1520/C0232_C0232M-26

[26] U.S. Army Engineer Waterways Experiment Station (WES), 1989. CRD C61–89A: TTest Method for Determining the Resistance of Freshly-Mixed Concrete to Washing Out in Water. U.S. Army Engineer Waterways Experiment Station (WES): Vicksburg, MI, USA. pp 1–3.

[27] ASTM International, 2023. ASTM C403/C403M-23: Standard Test Method for Time of Setting of Concrete Mixtures by Penetration Resistance. ASTM International: West Conshohocken, PA, USA. DOI: https://doi.org/10.1520/C0403_C0403M-23

[28] ASTM International, 2026. ASTM C109/C109M-26: Standard Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 50 mm [2 in.] Cube Specimens). ASTM International: West Conshohocken, PA, USA. DOI: https://doi.org/10.1520/C0109_C0109M-26

[29] Hwalla, J., Saba, M., Assaad, J.J., 2020. Suitability of metakaolin-based geopolymers for underwater applications. Materials and Structures. 53(5), 119. DOI: https://doi.org/10.1617/s11527-020-01546-0

[30] Zhuang, S., Wang, Q., Zhang, M., 2022. Water absorption behaviour of concrete: Novel experimental findings and model characterization. Journal of Building Engineering. 53, 104602. DOI: https://doi.org/10.1016/j.jobe.2022.104602

[31] Kabir, H., Garg, N., 2023. Rapid prediction of cementitious initial sorptivity via surface wettability. npj Materials Degradation. 7(1), 52. DOI: https://doi.org/10.1038/s41529-023-00371-4

[32] Belal, M.H., Heniegal, A.M., Ragheb, S.R., et al., 2026. Enhancing washout resistance and durability of slag-based underwater concrete incorporating eco-friendly ternary binders and recycled aggregates. Construction and Building Materials. 531, 146675. DOI: https://doi.org/10.1016/j.conbuildmat.2026.146675

[33] Li, L.G., Zhang, G.-H., 2024. Feasibility of underwater 3D printing: Effects of anti-washout admixtures on printability and strength of mortar. Journal of Building Engineering. 96, 110434. DOI: https://doi.org/10.1016/j.jobe.2024.110434

[34] Chen, W., Zhou, Y., Yu, Q., et al., 2024. Microscopic thickening mechanisms of hydroxypropyl methyl cellulose ether anti-washout admixture and its impact on cementitious material rheology and anti-dispersal performance. Journal of Building Engineering. 89, 109346. DOI: https://doi.org/10.1016/j.jobe.2024.109346

[35] Nia, S.B., Shafei, B., 2026. Advances in underwater concrete mixtures: Correlation of anti-washout requirements with rheological, mechanical, and durability properties. Results in Engineering. 31, 111439. DOI: https://doi.org/10.1016/j.rineng.2026.111439

[36] Guo, Y., Zhou, Z., Ma, A., et al., 2026. Phase separation and gelation behavior of the mixtures of welan gum and pea protein. Food Hydrocolloids. 171, 111774. DOI: https://doi.org/10.1016/j.foodhyd.2025.111774

[37] Tian, C., Chen, N., Su, Y., et al., 2024. Rheological properties and shrinkage crack resistance of welan gum-modified cementitious materials. Construction and Building Materials. 441, 137539. DOI: https://doi.org/10.1016/j.conbuildmat.2024.137539

Downloads

How to Cite

Assaad, J. J. (2026). Washout and Strength Behaviors of Underwater Concrete Containing Welan Gum and Slump Retainers . Journal of Building Material Science, 8(3), 105–121. https://doi.org/10.30564/jbms.v8i3.13659

Issue

Vol. 8, Iss. 3 (September 2026): In Progress

Article Type

Article

License

Copyright © 2026 Joseph Jean Assaad

Creative Commons License

This is an open access article under the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) License.

Crossref
Scopus
Google Scholar
Europe PMC