Effect of Starch-Based Water Reducer on Properties ofCement and Concrete

Abstract

Abstract: A new green starch-based water reducer (SWR) was prepared by oxidation-etherification reaction using corn starch as biological raw material, hydrogen peroxide (H₂O₂) as green oxidant and cationic quaternary ammonium salt as etherifying agent. In order to evaluate the effect of SWR on cement hydration performance, the change of functional groups in the process of SWR preparation was analyzed by FT-IR. The effects of SWR, PWR and NWR on water reducing ratio, zeta potential, fluidity of cement paste, strength of mortar and compressive strength of concrete were compared. The results show that carboxyl group and ether bond are introduced into SWR molecular chain. With the increase of water reducer content, the water reducing rate of SWR increases gradually, and it has a better water reducing effect than PWR and NWR. Based on the cement quality, when the mass fraction of SWR is 1.0%, the water reducing rate reaches 33%. Zeta potential analysis shows that the three have similar absolute potential values, but SWR has the largest absolute potential over time. When the mass fraction of water reducer is lower than 0.6%, the fluidity of cement paste of the three is similar, but the fluidity of NWR cement paste is more prominent when the content of water reducer continues to increase. The flexural strength and compressive strength of SWR sand specimens at 7 d and 28 d are basically between PWR and NWR sand specimens, the compressive strength of SWR concrete at 7 d is the lowest, and the compressive strength at 28 d is highest, up to 49.6 MPa, indicating that SWR plays a role in retarding setting. Comprehensive analysis shows that SWR water reducer has better water reducing and retarding effects, and guarantee the strength performance of concrete. The recommended mass fraction of SWR is 1.0%.

Key words: starch-based water reducer, oxidation-etherification reaction, cement hydration performance, concrete performance, mortar performance

CLC Number:

TU528.1

MIAO Fangli, YAO Zhihui, ZHANG Ding. Effect of Starch-Based Water Reducer on Properties ofCement and Concrete[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2021, 40(3): 758-764.

References

[1] 王田堂.淀粉改性制备水泥基材料减水剂的研究[D].绵阳:西南科技大学,2010.
WANG T T. The study on the cement-based material water-reducing agent prepared by modified starch[D]. Mianyang: Southwest University of Science and Technology, 2010 (in Chinese).
[2] 廖国胜,吴琼,汪琰皓.玉米淀粉改性聚羧酸减水剂试验研究[J].新型建筑材料,2018,45(7):139-142.
LIAO G S, WU Q, WANG Y H. Experimental study on corn starch modified polycarboxylate superplasticizer[J]. New Building Materials, 2018, 45(7): 139-142 (in Chinese).
[3] 何廷树,杨仁和,徐一伦,等.掺加改性淀粉制备聚羧酸减水剂及其应用[J].材料导报,2018,32(4):646-649.
HE T S, YANG R H, XU Y L, et al. Synthesis and application of polycarboxylate superplasticizer with modified starch[J]. Materials Review, 2018, 32(4): 646-649 (in Chinese).
[4] MYERS R J, L’H$\hat{O}$PITAL E, PROVIS J L, et al. Effect of temperature and aluminium on calcium (alumino) silicate hydrate chemistry under equilibrium conditions[J]. Cement and Concrete Research, 2015, 68: 83-93.
[5] 何辉,陈志健,吴家瑶,等.天然高分子基混凝土减水剂研究进展[J].高分子材料科学与工程,2016,32(11):178-183.
HE H, CHEN Z J, WU J Y, et al. Advances in concrete water-reducing agents based on natural polymers[J]. Polymer Materials Science & Engineering, 2016, 32(11): 178-183 (in Chinese).
[6] 吴井志,吕志锋,佘维娜,等.改性淀粉制减水剂的机理研究与展望[J].新型建筑材料,2015,42(9):4-7.
WU J Z, LYU Z F, SHE W N, et al. Mechanism and prospect of preparing superplasticizer by modified starch[J]. New Building Materials, 2015, 42(9): 4-7 (in Chinese).
[7] 赵平,严云,胡志华.改性淀粉作为混凝土缓凝减水剂的性能研究[J].混凝土与水泥制品,2012(7):1-5.
ZHAO P, YAN Y, HU Z H. Performance research of modified starch as water-reducing retarder for concrete[J]. China Concrete and Cement Products, 2012(7): 1-5 (in Chinese).
[8] 吴井志,乔敏,高南箫,等.用麦芽糊精制备聚羧酸系减水剂[J].硅酸盐学报,2017,45(11):1658-1664.
WU J Z, QIAO M, GAO N X, et al. Preparation of polycarboxylate superplasticizer water-reducing agent using maltodextrin[J]. Journal of the Chinese Ceramic Society, 2017, 45(11): 1658-1664 (in Chinese).
[9] 薛冬桦,吴洪发,孙国英,等.生物基减水剂对水泥水化进程影响及减水机理[J].建筑材料学报,2013,16(2):185-190.
XUE D H, WU H F, SUN G Y, et al. Influence of the novel bio-superplasticizer on cement hydration process and its water-reducing mechanism[J]. Journal of Building Materials, 2013, 16(2): 185-190 (in Chinese).
[10] 张坤,张莎莎,王晓俊,等.玉米秸秆糖醇黑液化学改性制备木质素基减水剂的研究[J].化工新型材料,2017,45(6):258-260.
ZHANG K, ZHANG S S, WANG X J, et al. Modification product of black liquor of sugar alcohol from corn stover as ligno-sulfate based plasticizer[J]. New Chemical Materials, 2017, 45(6): 258-260 (in Chinese).
[11] EINFELDT L, ALBRECHT G, KERN A, et al. Use of water-soluble polysaccharide derivatives as dispersing agents for mineral binder suspensions: US6893497[P]. 2005-05-17.
[12] 郑昌海,石海信,王爱荣,等.磺化接枝淀粉减水剂的合成及其结构与性能研究[J].应用化工,2018,47(12):2686-2691.
ZHENG C H, SHI H X, WANG A R, et al. Study on the synthesis, structure and properties of sulfonated graft starch as water reducing agent[J]. Applied Chemical Industry, 2018, 47(12): 2686-2691 (in Chinese).
[13] 吴家瑶,孙长江,何红荣,等.淀粉基混凝土减水剂作用机理研究[J].新型建筑材料,2017,44(8):37-40.
WU J Y, SUN C J, HE H R, et al. Study on the dispersion mechanism of starch based water reducing agent[J]. New Building Materials, 2017, 44(8): 37-40 (in Chinese).