Strikes were held on Friday, 21 June and again yesterday, with more disruption planned between today and Sunday.
Holiday travellers have been urged to expect longer than normal queues around the airport as the hub operates with fewer staff.
Industrial action will affect the airport between 10am and 2pm on Wednesday, 26 June, with a further strike to take place between the same hours on Thursday.
Travellers will also be affected by strike action on Friday, 28 June from 9.30am to 1.30pm and Sunday, 30 June from 5pm to 9pm.
In a recent ballot, airport staff who are Unite the union members voted overwhelmingly to walk out after the airport decided to close the final salary pension scheme.
The strike action comes following a 60-day consultation launched in January on the closure, which would break an Advisory, Conciliation and Arbritration Service (Acas) agreement made in 2016.
An initial pay offer of 1.8% tabled earlier this year was described by Unite, which represents around 500 workers at Glasgow Airport, as a "real-terms pay cut".
A total of 95 per cent of union members backed strike action on a turnout of 75 per cent.
Concerns have been raised over missed security threats by scanner staff during industrial action earlier this month.
Security hall software generates"threat images" of suspicious items, including knives and firearms, to ensure that scanner staff remain vigilant but a large number of these have been missed.
Around 190 computer generated images of outlawed or suspicious items were missed by scanner staff on 7 and 10 June, reports the Daily Star, compared with 70 misses in Aberdeen, whose staff are also locked in a pay and pensions dispute.
In a statement, Glasgow Airport managing director Mark Johnston commented: "Despite their best efforts to cause disruption, we have kept our airport open ensuring thousands of passengers and hundreds of flights have been able to travel and operate safely."
The airport has insisted that "robust contingency plans" have been put in place to ensure that the hub operates as normal.
In a statement, a spokesman for Glasgow Airport said: We will have our robust and safe contingency plans in place to ensure the travelling public are in no way impacted by the actions of Unite."They added: "We have, for the third year in a row, tabled a pay offer of 3% for 2019 and a guaranteed 3% pay increase for 2020.
"In regards to the final salary pension scheme, it is simply unaffordable with the cost to the company due to a rise to 24.7% per employee.
"We tabled a generous compensation package for the remaining members which account for less than 20% of the workforce. Those staff would transfer into the alternative pension scheme with an employer contribution of up to 16%.
"In addition, the company tabled a guaranteed bonus payment of £600 per employee."